freeCodeCamp/challenges/basic-javascript.json

{
  "name": "Basic JavaScript",
  "order": 6,
  "time": "5h",
  "challenges": [
    {
      "id": "bd7123c9c441eddfaeb4bdef",
      "title": "Comment your JavaScript Code",
      "description": [
        "Comments are lines of code that your computer will intentionally ignore. Comments are a great way to leave notes to yourself and to other people who will later need to figure out what that code does.",
        "Let's take a look at the two ways you can write comments in JavaScript.",
        "The double-slash comment will comment out the remainder of the text on the current line:",
        "<code>// This is a comment.</code>",
        "The slash-star-star-slash comment will comment out everything between the <code>/*</code> and the <code>*/</code> characters:",
        "<code>/* This is also a comment */</code>",
        "Try creating one of each."
      ],
      "tests": [
        "assert(editor.getValue().match(/(\\/\\/)...../g), 'message: Create a <code>//</code> style comment that contains at least five letters.');",
        "assert(editor.getValue().match(/(\\/\\*)[\\w\\W]{5,}(?=\\*\\/)/gm), 'message: Create a <code>/* */</code> style comment that contains at least five letters.');",
        "assert(editor.getValue().match(/(\\*\\/)/g), 'message: Make sure that you close the comment with a <code>*/</code>.');"
      ],
      "challengeSeed": [],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7123c9c441eddfaeb5bdef",
      "title": "Understand Boolean Values",
      "description": [
        "In computer science, <code>data structures</code> are things that hold data. JavaScript has seven of these. For example, the <code>Number</code> data structure holds numbers.",
        "Let's learn about the most basic data structure of all: the <code>Boolean</code>. Booleans can only hold the value of either true or false. They are basically little on-off switches.",
        "Let's modify our <code>welcomeToBooleans</code> function so that it will return <code>true</code> instead of <code>false</code> when the run button is clicked."
      ],
      "tests": [
        "assert(typeof(welcomeToBooleans()) === 'boolean', 'message: The <code>welcomeToBooleans()</code> function should return a boolean &#40;true/false&#41; value.');",
        "assert(welcomeToBooleans() === true, 'message: <code>welcomeToBooleans()</code> should return true.');"
      ],
      "challengeSeed": [
        "function welcomeToBooleans() {",
        "",
        "// Only change code below this line.",
        "",
        "  return false;",
        "",
        "// Only change code above this line.",
        "}"
      ],
      "tail": [
        "welcomeToBooleans();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7123c9c443eddfaeb5bdef",
      "title": "Declare JavaScript Variables",
      "description": [
        "When we store data in a <code>data structure</code>, we call it a <code>variable</code>. These variables are no different from the x and y variables you use in math.",
        "Let's create our first variable and call it \"myName\".",
        "You'll notice that in <code>myName</code>, we didn't use a space, and that the \"N\" is capitalized. JavaScript variables are written in <code>camel case</code>. An example of camel case is: camelCase.",
        "Now, use the <code>var</code> keyword to create a variable called <code>myName</code>. Set its value to your name, in double quotes.",
        "Look at the <code>ourName</code> example if you get stuck."
      ],
      "tests": [
        "assert((function(){if(typeof(myName) !== \"undefined\" && typeof(myName) === \"string\" && myName.length > 0){return true;}else{return false;}})(), 'message: <code>myName</code> should be a string that contains at least one character in it.');"
      ],
      "challengeSeed": [
        "var ourName = \"Free Code Camp\";",
        "",
        ""
      ],
      "tail": [
        "if(typeof(myName) !== \"undefined\"){(function(v){return v;})(myName);}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7123c9c444eddfaeb5bdef",
      "title": "Declare String Variables",
      "description": [
        "In the previous challenge, we used the code <code>var myName = \"your name\"</code>. This is what we call a <code>String</code> variable. It is nothing more than a \"string\" of characters. JavaScript strings are always wrapped in quotes.",
        "Now let's create two new string variables: <code>myFirstName</code> and <code>myLastName</code> and assign them the values of your first and last name, respectively."
      ],
      "tests": [
        "assert((function(){if(typeof(myFirstName) !== \"undefined\" && typeof(myFirstName) === \"string\" && myFirstName.length > 0){return true;}else{return false;}})(), 'message: <code>myFirstName</code> should be a string with at least one character in it.');",
        "assert((function(){if(typeof(myLastName) !== \"undefined\" && typeof(myLastName) === \"string\" && myLastName.length > 0){return true;}else{return false;}})(), 'message: <code>myLastName</code> should be a string with at least one character in it.');"
      ],
      "challengeSeed": [
        "var firstName = \"Alan\";",
        "var lastName = \"Turing\";",
        "",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(myFirstName) !== \"undefined\" && typeof(myLastName) !== \"undefined\"){(function(){return myFirstName + ', ' + myLastName;})();}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7123c9c448eddfaeb5bdef",
      "title": "Check the Length Property of a String Variable",
      "description": [
        "<code>Data structures</code> have <code>properties</code>. For example, <code>strings</code> have a property called <code>.length</code> that will tell you how many characters are in the string.",
        "For example, if we created a variable <code>var firstName = \"Charles\"</code>, we could find out how long the string \"Charles\" is by using the <code>firstName.length</code> property.",
        "Use the <code>.length</code> property to count the number of characters in the <code>lastName</code> variable."
      ],
      "tests": [
        "assert((function(){if(typeof(lastNameLength) !== \"undefined\" && typeof(lastNameLength) === \"number\" && lastNameLength === 8){return true;}else{return false;}})(), 'message: <code>lastNameLength</code> should be equal to eight.');",
        "assert((function(){if(editor.getValue().match(/\\.length/gi) && editor.getValue().match(/\\.length/gi).length >= 2 && editor.getValue().match(/var lastNameLength \\= 0;/gi) && editor.getValue().match(/var lastNameLength \\= 0;/gi).length >= 1){return true;}else{return false;}})(), 'message: You should be getting the length of <code>lastName</code> by using <code>.length</code> like this: <code>lastName.length</code>.');"
      ],
      "challengeSeed": [
        "var firstNameLength = 0;",
        "var lastNameLength = 0;",
        "var firstName = \"Ada\";",
        "",
        "firstNameLength = firstName.length;",
        "",
        "var lastName = \"Lovelace\";",
        "",
        "// Only change code below this line.",
        "",
        "lastNameLength = lastName;",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(lastNameLength) !== \"undefined\"){(function(){return lastNameLength;})();}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7123c9c549eddfaeb5bdef",
      "title": "Use Bracket Notation to Find the First Character in a String",
      "description": [
        "<code>Bracket notation</code> is a way to get a character at a specific <code>index</code> within a string.",
        "Computers don't start counting at 1 like humans do. They start at 0.",
        "For example, the character at index 0 in the word \"Charles\" is \"C\". So if <code>var firstName = \"Charles\"</code>, you can get the value of the first letter of the string by using <code>firstName[0]</code>.",
        "Use <code>bracket notation</code> to find the first character in the <code>lastName</code> variable and assign it to <code>firstLetterOfLastName</code>.",
        "Try looking at the <code>firstLetterOfFirstName</code> variable declaration if you get stuck."
      ],
      "tests": [
        "assert((function(){if(typeof(firstLetterOfLastName) !== \"undefined\" && editor.getValue().match(/\\[0\\]/gi) && typeof(firstLetterOfLastName) === \"string\" && firstLetterOfLastName === \"L\"){return true;}else{return false;}})(), 'message: The <code>firstLetterOfLastName</code> variable should have the value of <code>L</code>.');"
      ],
      "challengeSeed": [
        "var firstLetterOfFirstName = \"\";",
        "var firstLetterOfLastName = \"\";",
        "",
        "var firstName = \"Ada\";",
        "",
        "firstLetterOfFirstName = firstName[0];",
        "",
        "var lastName = \"Lovelace\";",
        "",
        "firstLetterOfLastName = lastName;",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(v){return v;})(firstLetterOfLastName);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7123c9c450eddfaeb5bdef",
      "title": "Use Bracket Notation to Find the Nth Character in a String",
      "description": [
        "You can also use <code>bracket notation</code> to get the character at other positions within a string.",
        "Remember that computers start counting at 0, so the first character is actually the zeroth character.",
        "Let's try to set <code>thirdLetterOfLastName</code> to equal the <code>third letter</code> of the <code>lastName</code> variable.",
        "Try looking at the <code>secondLetterOfFirstName</code> variable declaration if you get stuck."
      ],
      "tests": [
        "assert(thirdLetterOfLastName === 'v', 'message: The <code>thirdLetterOfLastName</code> variable should have the value of <code>v</code>.');"
      ],
      "challengeSeed": [
        "var firstName = \"Ada\";",
        "",
        "var secondLetterOfFirstName = firstName[1];",
        "",
        "var lastName = \"Lovelace\";",
        "",
        "var thirdLetterOfLastName = lastName;",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(v){return v;})(thirdLetterOfLastName);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7123c9c451eddfaeb5bdef",
      "title": "Use Bracket Notation to Find the Last Character in a String",
      "description": [
        "In order to get the last letter of a string, you can subtract one from the string's length.",
        "For example, if <code>var firstName = \"Charles\"</code>, you can get the value of the last letter of the string by using <code>firstName[firstName.length - 1]</code>.",
        "Use <code>bracket notation</code> to find the last character in the <code>lastName</code> variable.",
        "Try looking at the <code>lastLetterOfFirstName</code> variable declaration if you get stuck."
      ],
      "tests": [
        "assert(lastLetterOfLastName === \"e\", 'message: <code>lastLetterOfLastName</code> should be \"e\".');",
        "assert(editor.getValue().match(/\\.length/g).length === 2, 'message: You have to use <code>.length</code> to get the last letter.');"
      ],
      "challengeSeed": [
        "var firstName = \"Ada\";",
        "",
        "var lastLetterOfFirstName = firstName[firstName.length - 1];",
        "",
        "var lastName = \"Lovelace\";",
        "",
        "var lastLetterOfLastName = lastName;",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(v){return v;})(lastLetterOfLastName);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7123c9c452eddfaeb5bdef",
      "title": "Use Bracket Notation to Find the Nth-to-Last Character in a String",
      "description": [
        "You can use the same principle we just used to retrieve the last character in a string to retrieve the Nth-to-last character.",
        "For example, you can get the value of the third-to-last letter of the <code>var firstName = \"Charles\"</code> string by using <code>firstName[firstName.length - 3]</code>",
        "Use <code>bracket notation</code> to find the second-to-last character in the <code>lastName</code> string.",
        "Try looking at the <code>thirdToLastLetterOfFirstName</code> variable declaration if you get stuck."
      ],
      "tests": [
        "assert(secondToLastLetterOfLastName === 'c', 'message: <code>secondToLastLetterOfLastName</code> should be \"c\".');",
        "assert(editor.getValue().match(/\\.length/g).length === 2, 'message: You have to use <code>.length</code> to get the second last letter.');"
      ],
      "challengeSeed": [
        "var firstName = \"Ada\";",
        "",
        "var thirdToLastLetterOfFirstName = firstName[firstName.length - 3];",
        "",
        "var lastName = \"Lovelace\";",
        "",
        "var secondToLastLetterOfLastName = lastName;",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(v){return v;})(secondToLastLetterOfLastName);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c11feddfaeb3bdef",
      "title": "Add Two Numbers with JavaScript",
      "description": [
        "Let's try to add two numbers using JavaScript.",
        "JavaScript uses the <code>+</code> symbol for addition.",
        "Change the <code>0</code> so that sum will equal <code>20</code>."
      ],
      "tests": [
        "assert((function(){if(sum === 20 && editor.getValue().match(/\\+/g).length >= 2){return true;}else{return false;}})(), 'message: Make the variable <code>sum</code> equal 20.');"
      ],
      "challengeSeed": [
        "var sum = 10 + 0;",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return 'sum='+z;})(sum);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c11feddfaeb4bdef",
      "title": "Subtract One Number from Another with JavaScript",
      "description": [
        "We can also subtract one number from another.",
        "JavaScript uses the <code>-</code> symbol for subtraction.",
        "Change the <code>0</code> so that difference will equal <code>12</code>."
      ],
      "tests": [
        "assert((function(){if(difference === 12 && editor.getValue().match(/\\-/g)){return true;}else{return false;}})(), 'message: Make the variable <code>difference</code> equal 12.');"
      ],
      "challengeSeed": [
        "var difference = 45 - 0;",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return 'difference='+z;})(difference);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1231c1c11feddfaeb5bdef",
      "title": "Multiply Two Numbers with JavaScript",
      "description": [
        "We can also multiply one number by another.",
        "JavaScript uses the <code>*</code> symbol for multiplication.",
        "Change the <code>0</code> so that product will equal <code>80</code>."
      ],
      "tests": [
        "assert((function(){if(product === 80 && editor.getValue().match(/\\*/g)){return true;}else{return false;}})(), 'message: Make the variable <code>product</code> equal 80.');"
      ],
      "challengeSeed": [
        "var product = 8 * 0;",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return 'product='+z;})(product);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c11feddfaeb6bdef",
      "title": "Divide One Number by Another with JavaScript",
      "description": [
        "We can also divide one number by another.",
        "JavaScript uses the <code>/</code> symbol for division.",
        "Change the <code>0</code> so that quotient will equal <code>2</code>."
      ],
      "tests": [
        "assert((function(){if(quotient === 2 && editor.getValue().match(/var\\s*?quotient\\s*?\\=\\s*?\\d+\\s*?\\/\\s*?\\d+\\s*?;/g)){return true;}else{return false;}})(), 'message: Make the variable <code>quotient</code> equal 2.');"
      ],
      "challengeSeed": [
        "var quotient = 66 / 0;",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return 'quotient='+z;})(quotient);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1391c1c11feddfaeb4bdef",
      "title": "Create Decimal Numbers with JavaScript",
      "description": [
        "JavaScript number variables can also have decimals.",
        "Let's create a variable <code>myDecimal</code> and give it a decimal value."
      ],
      "tests": [
        "assert((function(){if(typeof(myDecimal) !== \"undefined\" && typeof(myDecimal) === \"number\" && editor.getValue().match(/\\./g).length >=2){return true;}else{return false;}})(), 'message: <code>myDecimal</code> should be a decimal point number.');"
      ],
      "challengeSeed": [
        "var ourDecimal = 5.7;",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(){if(typeof(myDecimal) !== \"undefined\"){return myDecimal;}})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7993c9c69feddfaeb7bdef",
      "title": "Multiply Two Decimals with JavaScript",
      "description": [
        "In JavaScript, you can also perform calculations with decimal numbers, just like whole numbers.",
        "Let's multiply two decimals together to get their product.",
        "Change the <code>0.0</code> so that product will equal <code>5.0</code>."
      ],
      "tests": [
        "assert((function(){if(product === 5.0 && editor.getValue().match(/\\*/g)){return true;}else{return false;}})(), 'message: Make the variable <code>product</code> equal 5.0.');"
      ],
      "challengeSeed": [
        "var product = 2.0 * 0.0;",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(y){return 'product='+y;})(product);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7993c9ca9feddfaeb7bdef",
      "title": "Divide one Decimal by Another with JavaScript",
      "description": [
        "Now let's divide one decimal by another.",
        "Change the <code>0.0</code> so that your quotient will equal <code>2.2</code>."
      ],
      "tests": [
        "assert((function(){if(quotient === 2.2 && editor.getValue().match(/\\//g)){return true;}else{return false;}})(), 'message: Make the variable <code>quotient</code> equal <code>2.2</code>.');"
      ],
      "challengeSeed": [
        "var quotient = 0.0 / 2.0;",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(y){return 'quotient='+y;})(quotient);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7993c9c69feddfaeb8bdef",
      "title": "Store Multiple Values in one Variable using JavaScript Arrays",
      "description": [
        "With JavaScript <code>array</code> variables, we can store several pieces of data in one place.",
        "You start an array declaration with an opening square bracket, end it with a closing square bracket, and put a comma between each entry, like this: <code>var sandwich = [\"peanut butter\", \"jelly\", \"bread\"]</code>.",
        "Now let's create a new array called <code>myArray</code> that contains both a <code>string</code> and a <code>number</code> (in that order).",
        "Refer to the commented code in the text editor if you get stuck."
      ],
      "tests": [
        "assert(typeof(myArray) == 'object', 'message: <code>myArray</code> should be an <code>array</code>.');",
        "assert(typeof(myArray[0]) !== 'undefined' && typeof(myArray[0]) == 'string', 'message: The first item in <code>myArray</code> should be a <code>string</code>.');",
        "assert(typeof(myArray[1]) !== 'undefined' && typeof(myArray[1]) == 'number', 'message: The second item in <code>myArray</code> should be a <code>number</code>.');"
      ],
      "challengeSeed": [
        "var array = [\"John\", 23];",
        "",
        "// Only change code below this line.",
        "",
        "var myArray = [];",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return z;})(myArray);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c11feddfaeb7bdef",
      "title": "Nest one Array within Another Array",
      "description": [
        "You can also nest arrays within other arrays, like this: <code>[[\"Bulls\", 23]]</code>.",
        "Let's now go create a nested array called <code>myArray</code>."
      ],
      "tests": [
        "assert(Array.isArray(myArray) && myArray.some(Array.isArray), 'message: <code>myArray</code> should have at least one array nested within another array.');"
      ],
      "challengeSeed": [
        "var ourArray = [[\"the universe\", \"everything\", 42]];",
        "",
        "// Only change code below this line.",
        "",
        "var myArray = [];",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9997c9c79feddfaeb9bdef",
      "title": "Access Array Data with Indexes",
      "description": [
        "We can access the data inside arrays using <code>indexes</code>.",
        "Array indexes are written in the same bracket notation that strings use, except that instead of specifying a character, they are specifying an entry in the array.",
        "For example:",
        "<code>var array = [1,2,3];</code>",
        "<code>array[0]; //equals 1</code>",
        "<code>var data = array[1];</code>",
        "Create a variable called <code>myData</code> and set it to equal the first value of <code>myArray</code>."
      ],
      "tests": [
        "assert((function(){if(typeof(myArray) != 'undefined' && typeof(myData) != 'undefined' && myArray[0] == myData){return true;}else{return false;}})(), 'message: The variable <code>myData</code> should equal the first value of <code>myArray</code>.');"
      ],
      "challengeSeed": [
        "var ourArray = [1,2,3];",
        "",
        "var ourData = ourArray[0]; // equals 1",
        "",
        "var myArray = [1,2,3];",
        "",
        "// Only change code below this line.",
        "",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(myArray) !== \"undefined\" && typeof(myData) !== \"undefined\"){(function(y,z){return 'myArray = ' + JSON.stringify(y) + ', myData = ' + JSON.stringify(z);})(myArray, myData);}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c11feddfaeb8bdef",
      "title": "Modify Array Data With Indexes",
      "description": [
        "We can also modify the data stored in arrays by using indexes.",
        "For example:",
        "<code>var ourArray = [3,2,1];</code>",
        "<code>ourArray[0] = 1; // equals [1,2,1]</code>",
        "Now modify the data stored at index 0 of <code>myArray</code> to the value of 3."
      ],
      "tests": [
        "assert((function(){if(typeof(myArray) != 'undefined' && myArray[0] == 3 && myArray[1] == 2 && myArray[2] == 3){return true;}else{return false;}})(), 'message: <code>myArray</code> should now be [3,2,3].');",
        "assert((function(){if(editor.getValue().match(/myArray\\[0\\]\\s?=\\s?/g)){return true;}else{return false;}})(), 'message: You should be using correct index to modify the value in <code>myArray</code>.');"
      ],
      "challengeSeed": [
        "var ourArray = [1,2,3];",
        "",
        "ourArray[1] = 3; // ourArray now equals [1,3,3].",
        "",
        "var myArray = [1,2,3];",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9994c9c69feddfaeb9bdef",
      "title": "Manipulate Arrays With pop()",
      "description": [
        "Another way to change the data in an array is with the <code>.pop()</code> function.",
        "<code>.pop()</code> is used to \"pop\" a value off of the end of an array. We can store this \"popped off\" variable by performing <code>pop()</code> within a variable declaration.",
        "Any type of data structure can be \"popped\" off of an array - numbers, strings, even nested arrays.",
        "Use the <code>.pop()</code> function to remove the last item from <code>myArray</code>, assigning the \"popped off\" value to <code>removedFromMyArray</code>."
      ],
      "tests": [
        "assert((function(d){if(d[0] == 'John' && d[1] == 23 && d[2] == undefined){return true;}else{return false;}})(myArray), 'message: <code>myArray</code> should only contain <code>[\"John\", 23]</code>.');",
        "assert((function(d){if(d[0] == 'cat' && d[1] == 2 && d[2] == undefined){return true;}else{return false;}})(removedFromMyArray), 'message: <code>removedFromMyArray</code> should only contain <code>[\"cat\", 2]</code>.');"
      ],
      "challengeSeed": [
        "var ourArray = [1,2,3];",
        "",
        "var removedFromOurArray = ourArray.pop(); // removedFromOurArray now equals 3, and ourArray now equals [1,2]",
        "",
        "var myArray = [\"John\", 23, [\"cat\", 2]];",
        "",
        "// Only change code below this line.",
        "",
        "var removedFromMyArray;",
        "",
        "// Only change code above this line.",
        "",
        "(function(y, z){return 'myArray = ' + JSON.stringify(y) + ' & removedFromMyArray = ' + JSON.stringify(z);})(myArray, removedFromMyArray);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9995c9c69feddfaeb9bdef",
      "title": "Manipulate Arrays With push()",
      "description": [
        "Not only can you <code>pop()</code> data off of the end of an array, you can also <code>push()</code> data onto the end of an array.",
        "Push <code>[\"dog\", 3]</code> onto the end of the <code>myArray</code> variable."
      ],
      "tests": [
        "assert((function(d){if(d[2] != undefined && d[0] == 'John' && d[1] == 23 && d[2][0] == 'dog' && d[2][1] == 3 && d[2].length == 2){return true;}else{return false;}})(myArray), 'message: <code>myArray</code> should now equal <code>[\"John\", 23, [\"dog\", 3]]</code>.');"
      ],
      "challengeSeed": [
        "var ourArray = [\"Stimpson\", \"J\", [\"cat\"]];",
        "",
        "ourArray.pop(); // ourArray now equals [\"Stimpson\", \"J\"]",
        "",
        "ourArray.push([\"happy\", \"joy\"]); // ourArray now equals [\"Stimpson\", \"J\", [\"happy\", \"joy\"]]",
        "",
        "var myArray = [\"John\", 23, [\"cat\", 2]];",
        "",
        "myArray.pop();",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return 'myArray = ' + JSON.stringify(z);})(myArray);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9996c9c69feddfaeb9bdef",
      "title": "Manipulate Arrays With shift()",
      "description": [
        "<code>pop()</code> always removes the last element of an array. What if you want to remove the first?",
        "That's where <code>.shift()</code> comes in. It works just like <code>.pop()</code>, except it removes the first element instead of the last.",
        "Use the <code>.shift()</code> function to remove the first item from <code>myArray</code>, assigning the \"shifted off\" value to <code>removedFromMyArray</code>."
      ],
      "tests": [
        "assert((function(d){if(d[0] == 23 && d[1][0] == 'dog' && d[1][1] == 3 && d[2] == undefined){return true;}else{return false;}})(myArray), 'message: <code>myArray</code> should now equal <code>[23, [\"dog\", 3]]</code>.');",
        "assert((function(d){if(d === 'John' && typeof(removedFromMyArray) === 'string'){return true;}else{return false;}})(removedFromMyArray), 'message: <code>removedFromMyArray</code> should contain <code>\"John\"</code>.');"
      ],
      "challengeSeed": [
        "var ourArray = [\"Stimpson\", \"J\", [\"cat\"]];",
        "",
        "removedFromOurArray = ourArray.shift(); // removedFromOurArray now equals \"Stimpson\" and ourArray now equals [\"J\", [\"cat\"]].",
        "",
        "var myArray = [\"John\", 23, [\"dog\", 3]];",
        "",
        "// Only change code below this line.",
        "",
        "var removedFromMyArray;",
        "",
        "// Only change code above this line.",
        "",
        "",
        "(function(y, z){return 'myArray = ' + JSON.stringify(y) + ' & removedFromMyArray = ' + JSON.stringify(z);})(myArray, removedFromMyArray);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9997c9c69feddfaeb9bdef",
      "title": "Manipulate Arrays With unshift()",
      "description": [
        "Not only can you <code>shift</code> elements off of the beginning of an array, you can also <code>unshift</code> elements onto the beginning of an array.",
        "<code>unshift()</code> works exactly like <code>push()</code>, but instead of adding the element at the end of the array, <code>unshift()</code> adds the element at the beginning of the array.",
        "Add <code>\"Paul\"</code> onto the beginning of the <code>myArray</code> variable using <code>unshift()</code>."
      ],
      "tests": [
        "assert((function(d){if(typeof(d[0]) === \"string\" && d[0].toLowerCase() == 'paul' && d[1] == 23 && d[2][0] != undefined && d[2][0] == 'dog' && d[2][1] != undefined && d[2][1] == 3){return true;}else{return false;}})(myArray), 'message: <code>myArray</code> should now have [\"Paul\", 23, [\"dog\", 3]]).');"
      ],
      "challengeSeed": [
        "var ourArray = [\"Stimpson\", \"J\", [\"cat\"]];",
        "",
        "ourArray.shift(); // ourArray now equals [\"J\", [\"cat\"]]",
        "",
        "ourArray.unshift(\"happy\"); // ourArray now equals [\"happy\", \"J\", [\"cat\"]]",
        "",
        "var myArray = [\"John\", 23, [\"dog\", 3]];",
        "",
        "myArray.shift();",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(y, z){return 'myArray = ' + JSON.stringify(y);})(myArray);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9997c9c89feddfaeb9bdef",
      "title": "Write Reusable JavaScript with Functions",
      "description": [
        "In JavaScript, we can divide up our code into reusable parts called functions.",
        "Here's an example of a function:",
        "<code>function functionName(a, b) {</code>",
        "<code>&nbsp;&nbsp;return a + b;</code>",
        "<code>}</code>",
        "After writing the above lines in our code, we can then pass values to our function and the result following the <code>return</code> statement will be returned.",
        "For example, we can pass numbers <code>4</code> and <code>2</code> by “calling” the function later in our code like this: <code>functionName(4, 2)</code>.",
        "In this example, the function will return the number <code>6</code> as this is the result of <code>4 + 2</code>.",
        "Create and call a function called <code>myFunction</code> that returns the sum of <code>a</code> and <code>b</code>."
      ],
      "tests": [
        "assert((function(){if(typeof(f) !== \"undefined\" && f === a + b){return true;}else{return false;}})(), 'message: Your function should return the value of <code>a + b</code>.');"
      ],
      "challengeSeed": [
        "var a = 4;",
        "var b = 5;",
        "",
        "function ourFunction(a, b) {",
        "  return a - b;",
        "}",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(myFunction) !== \"undefined\"){",
        "var f=myFunction(a,b);",
        "(function(){return f;})();",
        "}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9998c9c99feddfaeb9bdef",
      "title": "Build JavaScript Objects",
      "description": [
        "You may have heard the term <code>object</code> before.",
        "Objects are similar to <code>arrays</code>, except that instead of using indexes to access and modify their data, you access the data in objects through what are called <code>properties</code>.",
        "Here's a sample object:",
        "<code>var cat = {</code>",
        "<code>&nbsp;&nbsp;\"name\": \"Whiskers\",</code>",
        "<code>&nbsp;&nbsp;\"legs\": 4,</code>",
        "<code>&nbsp;&nbsp;\"tails\": 1,</code>",
        "<code>&nbsp;&nbsp;\"enemies\": [\"Water\", \"Dogs\"]</code>",
        "<code>};</code>",
        "</code>",
        "Objects are useful for storing data in a structured way, and can represent real world objects, like a cat.",
        "Let's try to make an object that represents a dog called <code>myDog</code> which contains the properties <code>\"name\"</code> (a string), <code>\"legs\"</code>, <code>\"tails\"</code> and <code>\"friends\"</code>.",
        "You can set these object properties to whatever values you want, as long <code>\"name\"</code> is a string, <code>\"legs\"</code> and <code>\"tails\"</code> are numbers, and <code>\"friends\"</code> is an array."
      ],
      "tests": [
        "assert((function(z){if(z.hasOwnProperty(\"name\") && z.name !== undefined && typeof(z.name) === \"string\"){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>name</code> and it should be a <code>string</code>.');",
        "assert((function(z){if(z.hasOwnProperty(\"legs\") && z.legs !== undefined && typeof(z.legs) === \"number\"){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>legs</code> and it should be a <code>number</code>.');",
        "assert((function(z){if(z.hasOwnProperty(\"tails\") && z.tails !== undefined && typeof(z.tails) === \"number\"){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>tails</code> and it should be a <code>number</code>.');",
        "assert((function(z){if(z.hasOwnProperty(\"friends\") && z.friends !== undefined && Array.isArray(z.friends)){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>friends</code> and it should be an <code>array</code>.');"
      ],
      "challengeSeed": [
        "var ourDog = {",
        "  \"name\": \"Camper\",",
        "  \"legs\": 4,",
        "  \"tails\": 1,",
        "  \"friends\": [\"everything!\"]",
        "};",
        "",
        "// Only change code below this line.",
        "",
        "var myDog = {",
        "",
        "",
        "",
        "",
        "};",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return z;})(myDog);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9999c9c99feddfaeb9bdef",
      "title": "Update the Properties of a JavaScript Object",
      "description": [
        "After you've created a JavaScript object, you can update its properties at any time just like you would update any other variable.",
        "For example, let's look at <code>ourDog</code>:",
        "<code>var ourDog = {</code>",
        "<code>&nbsp;&nbsp;\"name\": \"Camper\",</code>",
        "<code>&nbsp;&nbsp;\"legs\": 4,</code>",
        "<code>&nbsp;&nbsp;\"tails\": 1,</code>",
        "<code>&nbsp;&nbsp;\"friends\": [\"everything!\"]</code>",
        "<code>};</code>",
        "Since he's a particularly happy dog, let's change his name to \"Happy Camper\". Here's how we update his object's name property:",
        "<code>ourDog.name = \"Happy Camper\";</code>",
        "Now when we run <code>return ourDog.name</code>, instead of getting \"Camper\", we'll get his new name, \"Happy Camper\".",
        "Let's update the <code>myDog</code> object's name property. Let's change her name from \"Coder\" to \"Happy Coder\"."
      ],
      "tests": [
        "assert(/happy coder/gi.test(myDog.name), 'message: Update <code>myDog</code>&apos;s <code>\"name\"</code> property to equal \"Happy Coder\".');"
      ],
      "challengeSeed": [
        "var ourDog = {",
        "  \"name\": \"Camper\",",
        "  \"legs\": 4,",
        "  \"tails\": 1,",
        "  \"friends\": [\"everything!\"]",
        "};",
        "",
        "ourDog.name = \"Happy Camper\";",
        "",
        "var myDog = {",
        "  \"name\": \"Coder\",",
        "  \"legs\": 4,",
        "  \"tails\": 1,",
        "  \"friends\": [\"Free Code Camp Campers\"]",
        "};",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return z;})(myDog);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9999c9c99feedfaeb9bdef",
      "title": "Add New Properties to a JavaScript Object",
      "description": [
        "You can add new properties to existing JavaScript objects the same way you would modify them.",
        "Here's how we would add a <code>\"bark\"</code> property to <code>ourDog</code>:",
        "<code>ourDog.bark = \"bow-wow\";</code>",
        "Now when we run <code>return ourDog.bark</code>, we'll get his bark, \"bow-wow\".",
        "Let's add a <code>\"bark\"</code> property to <code>myDog</code> and set it to a dog sound, such as \"woof\"."
      ],
      "tests": [
        "assert(myDog.bark !== undefined, 'message: Add the property <code>\"bark\"</code> to <code>myDog</code>.');"
      ],
      "challengeSeed": [
        "var ourDog = {",
        "  \"name\": \"Camper\",",
        "  \"legs\": 4,",
        "  \"tails\": 1,",
        "  \"friends\": [\"everything!\"]",
        "};",
        "",
        "ourDog.bark = \"bow-wow\";",
        "",
        "var myDog = {",
        "  \"name\": \"Happy Coder\",",
        "  \"legs\": 4,",
        "  \"tails\": 1,",
        "  \"friends\": [\"Free Code Camp Campers\"]",
        "};",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return z;})(myDog);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9999c9c99fdddfaeb9bdef",
      "title": "Delete Properties from a JavaScript Object",
      "description": [
        "We can also delete properties from objects like this:",
        "<code>delete ourDog.bark;</code>",
        "Let's delete the <code>\"tails\"</code> property from <code>myDog</code>."
      ],
      "tests": [
        "assert(myDog.tails === undefined, 'message: Delete the property <code>\"tails\"</code> from <code>myDog</code>.');"
      ],
      "challengeSeed": [
        "var ourDog = {",
        "  \"name\": \"Camper\",",
        "  \"legs\": 4,",
        "  \"tails\": 1,",
        "  \"friends\": [\"everything!\"],",
        "  \"bark\": \"bow-wow\"",
        "};",
        "",
        "delete ourDog.bark;",
        "",
        "var myDog = {",
        "  \"name\": \"Happy Coder\",",
        "  \"legs\": 4,",
        "  \"tails\": 1,",
        "  \"friends\": [\"Free Code Camp Campers\"],",
        "  \"bark\": \"woof\"",
        "};",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "(function(z){return z;})(myDog);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c11feddfaeb5bdef",
      "title": "Iterate with JavaScript For Loops",
      "description": [
        "You can run the same code multiple times by using a loop.",
        "The most common type of JavaScript loop is called a \"for loop\" because it runs \"for\" a specific number of times.",
        "For loops are declared with three optional expressions seperated by semicolons:",
        "<code>for ([initialization]; [condition]; [final-expression])</code>",
        "The <code>initialization</code> statement is executed one time only before the loop starts. It is typically used to define and setup your loop variable.",
        "The <code>condition</code> statement is evaluated at the beginning of every loop iteration and will continue as long as it evalutes to <code>true</code>. When <code>condition</code> is <code>false</code> at the start of the iteration, the loop will stop executing.  This means if <code>condition</code> starts as <code>false</code>, your loop will never execute.",
        "The <code>final-expression</code> is executed at the end of each loop iteration, prior to the next <code>condition</code> check and is usually used to increment or decrement your loop counter.",
        "In the following example we initialize with <code>i = 0</code> and iterate while our condition <code>i < 5</code> is true.  We'll increment <code>i</code> by <code>1</code> in each loop iteration with <code>i++</code> as our <code>final-expression</code>.",
        "<code>var ourArray = [];</code>",
        "<code>for (var i = 0; i < 5; i++) {</code>",
        "<code>&nbsp;&nbsp;ourArray.push(i);</code>",
        "<code>}</code>",
        "<code>ourArray</code> will now contain <code>[0,1,2,3,4]</code>.",
        "Let's use a <code>for</code> loop to work to push the values 1 through 5 onto <code>myArray</code>."
      ],
      "tests": [
        "assert(editor.getValue().match(/for\\s*\\(/g).length > 1, 'message: You should be using a <code>for</code> loop for this.');",
        "assert.deepEqual(myArray, [1,2,3,4,5], 'message: <code>myArray</code> should equal <code>[1,2,3,4,5]</code>.');"
      ],
      "challengeSeed": [
        "var ourArray = [];",
        "",
        "for (var i = 0; i < 5; i++) {",
        "  ourArray.push(i);",
        "}",
        "",
        "var myArray = [];",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}",
        ""
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"56104e9e514f539506016a5c",
      "title": "Iterate Odd Numbers With a For Loop",
      "description":[
        "For loops don't have to iterate one at a time. By changing our <code>final-expression</code>, we can count by even numbers.",
        "We'll start at <code>i = 0</code> and loop while <code>i < 10</code>.  We'll increment <code>i</code> by 2 each loop with <code>i += 2</code>.",
        "<code>var ourArray = [];</code>",
        "<code>for (var i = 0; i < 10; i += 2) {</code>",
        "<code>&nbsp;&nbsp;ourArray.push(i);</code>",
        "<code>}</code>",
        "<code>ourArray</code> will now contain <code>[0,2,4,6,8]</code>.",
        "Let's change our <code>initialization</code> and <code>final-expression</code> so we can count by odd numbers.",
        "Push the odd numbers from 1 through 9 to <code>myArray</code> using a <code>for</code> loop."
      ],
      "tests":[
        "assert(editor.getValue().match(/for\\s*\\(/g).length > 1, 'message: You should be using a <code>for</code> loop for this.');",
        "assert.deepEqual(myArray, [1,3,5,7,9], 'message: <code>myArray</code> should equal <code>[1,3,5,7,9]</code>.');"
      ],
      "challengeSeed":[
        "var ourArray = [];",
        "",
        "for (var i = 0; i < 10; i += 2) {",
        "  ourArray.push(i);",
        "}",
        "",
        "var myArray = [];",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}",
        ""
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"56105e7b514f539506016a5e",
      "title": "Count Backwards With a For Loop",
      "description":[
        "A for loop can also count backwards, so long as we can define the right conditions.",
        "In order to count backwards by twos, we'll need to change our <code>initialization</code>, <code>condition</code>, and <code>final-expression</code>.",
        "We'll start at <code>i = 10</code> and loop while <code>i > 0</code>.  We'll decrement <code>i</code> by 2 each loop with <code>i -= 2</code>.",
        "<code>var ourArray = [];</code>",
        "<code>for (var i = 10; i > 0; i -= 2) {</code>",
        "<code>&nbsp;&nbsp;ourArray.push(i);</code>",
        "<code>}</code>",
        "<code>ourArray</code> will now contain <code>[10,8,6,4,2]</code>.",
        "Let's change our <code>initialization</code> and <code>final-expression</code> so we can count backward by twos by odd numbers.",
        "Push the odd numbers from 9 through 1 to <code>myArray</code> using a <code>for</code> loop."
      ],
      "tests":[
        "assert(editor.getValue().match(/for\\s*\\(/g).length > 1, 'message: You should be using a <code>for</code> loop for this.');",
        "assert.deepEqual(myArray, [9,7,5,3,1], 'message: <code>myArray</code> should equal <code>[9,7,5,3,1]</code>.');"
      ],
      "challengeSeed":[
        "var ourArray = [];",
        "",
        "for (var i = 10; i > 0; i -= 2) {",
        "  ourArray.push(i);",
        "}",
        "",
        "var myArray = [];",
        "",
        "// Only change code below this line.",
        "",
        "",
        ""
      ],
      "tail": [
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c11feddfaeb1bdef",
      "title": "Iterate with JavaScript While Loops",
      "description": [
        "You can run the same code multiple times by using a loop.",
        "Another type of JavaScript loop is called a \"while loop\", because it runs \"while\" something is true and stops once that something is no longer true.",
        "<code>var ourArray = [];</code>",
        "<code>var i = 0;</code>",
        "<code>while(i < 5) {</code>",
        "<code>&nbsp;&nbsp;ourArray.push(i);</code>",
        "<code>&nbsp;&nbsp;i++;</code>",
        "<code>}</code>",
        "Let's try getting a while loop to work by pushing values to an array.",
        "Push the numbers 0 through 4 to <code>myArray</code> using a <code>while</code> loop."
      ],
      "tests": [
        "assert(editor.getValue().match(/while/g), 'message: You should be using a <code>while</code> loop for this.');",
        "assert.deepEqual(myArray, [0,1,2,3,4], 'message: <code>myArray</code> should equal <code>[0,1,2,3,4]</code>.');"
      ],
      "challengeSeed": [
        "var myArray = [];",
        "",
        "// Only change code below this line.",
        "",
        "",
        "",
        "// Only change code above this line.",
        "",
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}",
        ""
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c11feddfaeb9bdef",
      "title": "Generate Random Fractions with JavaScript",
      "description": [
        "Random numbers are useful for creating random behavior.",
        "JavaScript has a <code>Math.random()</code> function that generates a random decimal number between 0 and 1.",
        "Change <code>myFunction</code> to return a random number instead of returning <code>0</code>.",
        "Note that you can return a function, just like you would return a variable or value."
      ],
      "tests": [
        "assert(typeof(myFunction()) === \"number\", 'message: <code>myFunction</code> should return a random number.');",
        "assert((myFunction()+''). match(/\\./g), 'message: The number returned by <code>myFunction</code> should be a decimal.');",
        "assert(editor.getValue().match(/Math\\.random/g).length >= 0, 'message: You should be using <code>Math.random</code> to generate the random decimal number.');"
      ],
      "challengeSeed": [
        "function myFunction() {",
        "",
        "  // Only change code below this line.",
        "",
        "  return 0;",
        "",
        "  // Only change code above this line.",
        "}",
        "",
        "(function(){return myFunction();})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c12feddfaeb1bdef",
      "title": "Generate Random Whole Numbers with JavaScript",
      "description": [
        "It's great that we can generate random decimal numbers, but it's even more useful if we use it to generate random whole numbers.",
        "First, let's use <code>Math.random()</code> to generate a random decimal.",
        "Then let's multiply this random decimal by 20.",
        "Finally, let's use another function, <code>Math.floor()</code> to round the number down to its nearest whole number.",
        "This technique will gives us a whole number between 0 and 19.",
        "Note that because we're rounding down, it's impossible to actually get 20.",
        "Putting everything together, this is what our code looks like:",
        "<code>Math.floor(Math.random() * 20);</code>",
        "See how <code>Math.floor</code> takes <code>(Math.random() * 20)</code> as its argument? That's right - you can pass a function to another function as an argument.",
        "Let's use this technique to generate and return a random whole number between 0 and 9."
      ],
      "tests": [
        "assert(editor.getValue().match(/var\\srandomNumberBetween0and19\\s=\\sMath.floor\\(Math.random\\(\\)\\s\\*\\s20\\);/).length == 1, 'message: The first line of code should not be changed.');",
        "assert(typeof(myFunction()) === \"number\" && (function(){var r = myFunction();return Math.floor(r) === r;})(), 'message: The result of <code>myFunction</code> should be a whole number.');",
        "assert(editor.getValue().match(/Math.random/g).length > 1, 'message: You should be using <code>Math.random</code> to generate a random number.');",
        "assert(editor.getValue().match(/\\(\\s*?Math.random\\s*?\\(\\s*?\\)\\s*?\\*\\s*?10\\s*?\\)/g) || editor.getValue().match(/\\(\\s*?10\\s*?\\*\\s*?Math.random\\s*?\\(\\s*?\\)\\s*?\\)/g), 'message: You should have multiplied the result of <code>Math.random</code> by 10 to make it a number that is between zero and nine.');",
        "assert(editor.getValue().match(/Math.floor/g).length > 1, 'message: You should use <code>Math.floor</code> to remove the decimal part of the number.');"
      ],
      "challengeSeed": [
        "var randomNumberBetween0and19 = Math.floor(Math.random() * 20);",
        "",
        "function myFunction() {",
        "",
        "  // Only change code below this line.",
        "",
        "  return Math.random();",
        "",
        "  // Only change code above this line.",
        "}"
      ],
      "tail":[
        "(function(){return myFunction();})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c12feddfaeb2bdef",
      "title": "Generate Random Whole Numbers within a Range",
      "description": [
        "Instead of generating a random number between zero and a given number like we did before, we can generate a random number that falls within a range of two specific numbers.",
        "To do this, we'll define a minimum number <code>min</code> and a maximum number <code>max</code>.",
        "Here's the formula we'll use. Take a moment to read it and try to understand what this code is doing:",
        "<code>Math.floor(Math.random() * (max - min + 1)) + min</code>",
        "Define two variables: <code>myMin</code> and <code>myMax</code>, and set them both equal to numbers.",
        "Then create a function called <code>myFunction</code> that returns a random number that's greater than or equal to <code>myMin</code>, and is less than or equal to <code>myMax</code>."
      ],
      "tests": [
        "assert(myFunction() >= myMin, 'message: The random number generated by <code>myFunction</code> should be greater than or equal to your minimum number, <code>myMin</code>.');",
        "assert(myFunction() <= myMax, 'message: The random number generated by <code>myFunction</code> should be less than or equal to your maximum number, <code>myMax</code>.');",
        "assert(myFunction() % 1 === 0 , 'message: The random number generated by <code>myFunction</code> should be an integer, not a decimal.');",
        "assert((function(){if(editor.getValue().match(/myMax/g).length > 1 && editor.getValue().match(/myMin/g).length > 2 && editor.getValue().match(/Math.floor/g) && editor.getValue().match(/Math.random/g)){return true;}else{return false;}})(), 'message: <code>myFunction()</code> should use use both <code>myMax</code> and <code>myMin</code>, and return a random number in your range.');"
      ],
      "challengeSeed": [
        "var ourMin = 1;",
        "",
        "var ourMax = 9;",
        "",
        "function ourFunction() {",
        "",
        "  return Math.floor(Math.random() * (ourMax - ourMin + 1)) + ourMin;",
        "",
        "}",
        "",
        "// Only change code below this line.",
        "",
        "var myMin;",
        "",
        "var myMax;",
        "",
        "function myFunction() {",
        "",
        "  return;",
        "",
        "}",
        "",
        "// Only change code above this line.",
        "",
        "",
        "(function(){return myFunction();})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c12feddfaeb3bdef",
      "title": "Use Conditional Logic with If and Else Statements",
      "description": [
        "We can use <code>if</code> statements in JavaScript to only execute code if a certain condition is met.",
        "<code>if</code> statements require some sort of boolean condition to evaluate.",
        "For example:",
        "<code>var x = 1;</code>",
        "<code>if (x === 2) {</code>",
        "<code>&nbsp;&nbsp;return 'x is 2';</code>",
        "<code>} else {</code>",
        "<code>&nbsp;&nbsp;return 'x is not 2';</code>",
        "<code>}</code>",
        "Let's use <code>if</code> and <code>else</code> statements to make a coin-flip game.",
        "Create <code>if</code> and <code>else</code> statements to return the string <code>\"heads\"</code> if the flip variable is zero, or else return the string <code>\"tails\"</code> if the flip variable is not zero."
      ],
      "tests": [
        "assert(editor.getValue().match(/if/g).length >= 2, 'message: Create a new if statement.');",
        "assert(editor.getValue().match(/else/g).length >= 1, 'message: Created a new else statement.');",
        "assert((function(){var result = myFunction();if(result === 'heads' || result === 'tails'){return true;} else {return false;}})(), 'message: <code>myFunction</code> should either return <code>heads</code> or <code>tails</code>.');",
        "assert((function(){var result = myFunction();if(result === 'heads' && flip === 0 || result === 'tails' && flip !== 0){return true;} else {return false;}})(), 'message: <code>myFunction</code> should return <code>heads</code> when flip equals 0 and <code>tails</code> when flip equals 1.');"
      ],
      "challengeSeed": [
        "var flip = Math.floor(Math.random() * (1 - 0 + 1)) + 0;",
        "",
        "function myFunction() {",
        "",
        "  // Only change code below this line.",
        "",
        "",
        "",
        "  // Only change code above this line.",
        "",
        "}",
        "",
        "var result = myFunction();if(typeof(flip) !== \"undefined\" && typeof(flip) === \"number\" && typeof(result) !== \"undefined\" && typeof(result) === \"string\"){(function(y,z){return 'flip = ' + y.toString() + ', text = ' + z;})(flip, result);}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c12feddfaeb6bdef",
      "title": "Sift through Text with Regular Expressions",
      "description": [
        "<code>Regular expressions</code> are used to find certain words or patterns inside of <code>strings</code>.",
        "For example, if we wanted to find the word <code>the</code> in the string <code>The dog chased the cat</code>, we could use the following <code>regular expression</code>: <code>/the/gi</code>",
        "Let's break this down a bit:",
        "<code>the</code> is the pattern we want to match.",
        "<code>g</code> means that we want to search the entire string for this pattern instead of just the first match.",
        "<code>i</code> means that we want to ignore the case (uppercase or lowercase) when searching for the pattern.",
        "<code>Regular expressions</code> are written by surrounding the pattern with <code>/</code> symbols.",
        "Let's try selecting all the occurrences of the word <code>and</code> in the string <code>Ada Lovelace and Charles Babbage designed the first computer and the software that would have run on it</code>.",
        "We can do this by replacing the <code>.</code> part of our regular expression with the word <code>and</code>."
      ],
      "tests": [
        "assert(test==2, 'message: Your <code>regular expression</code> should find two occurrences of the word <code>and</code>.');",
        "assert(editor.getValue().match(/\\/and\\/gi/), 'message: Use <code>regular expressions</code> to find the word <code>and</code> in <code>testString</code>.');"
      ],
      "challengeSeed": [
        "var test = (function() {",
        "  var testString = \"Ada Lovelace and Charles Babbage designed the first computer and the software that would have run on it.\";",
        "  var expressionToGetSoftware = /software/gi;",
        "",
        "  // Only change code below this line.",
        "",
        "  var expression = /./gi;",
        "",
        "  // Only change code above this line.",
        "",
        "  return testString.match(expression).length;",
        "})();(function(){return test;})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c12feddfaeb7bdef",
      "title": "Find Numbers with Regular Expressions",
      "description": [
        "We can use special selectors in <code>Regular Expressions</code> to select a particular type of value.",
        "One such selector is the digit selector <code>\\d</code> which is used to retrieve the numbers in a string.",
        "It is used like this: <code>/\\d/g</code>.",
        "For numbers this is often written as <code>/\\d+/g</code>, where the <code>+</code> following the digit selector allows this regular expression to match multi-digit numbers.",
        "Use the <code>\\d</code> selector to select the number of numbers in the string, allowing for the possibility of multi-digit numbers."
      ],
      "tests": [
        "assert(editor.getValue().match(/\\/\\\\d\\+\\//g), 'message: Use the <code>/\\d+/g</code> regular expression to find the numbers in <code>testString</code>.');",
        "assert(test === 2, 'message: Your regular expression should find two numbers in <code>testString</code>.');"
      ],
      "challengeSeed": [
        "var test = (function() {",
        "",
        "  var testString = \"There are 3 cats but 4 dogs.\";",
        "",
        "  // Only change code below this line.",
        "",
        "  var expression = /.+/g;",
        "",
        "  // Only change code above this line.",
        "",
        "  return testString.match(expression).length;",
        "",
        "})();(function(){return test;})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c12feddfaeb8bdef",
      "title": "Find Whitespace with Regular Expressions",
      "description": [
        "We can also use regular expression selectors like <code>\\s</code> to find whitespace in a string.",
        "The whitespace characters are <code>\" \"</code> (space), <code>\\r</code> (the carriage return), <code>\\n</code> (newline), <code>\\t</code> (tab), and <code>\\f</code> (the form feed).",
        "The whitespace regular expression looks like this:",
        "<code>/\\s+/g</code>",
        "Use it to select all the whitespace characters in the sentence string."
      ],
      "tests": [
        "assert(editor.getValue().match(/\\/\\\\s\\+\\//g), 'message: Use the <code>/\\s+/g</code> regular expression to find the spaces in <code>testString</code>.');",
        "assert(test === 7, 'message: Your regular expression should find seven spaces in <code>testString</code>.');"
      ],
      "challengeSeed": [
        "var test = (function(){",
        "  var testString = \"How many spaces are there in this sentence?\";",
        "",
        "  // Only change code below this line.",
        "",
        "  var expression = /.+/g;",
        "",
        "  // Only change code above this line.",
        "",
        "  return testString.match(expression).length;",
        "",
        "})();(function(){return test;})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c13feddfaeb3bdef",
      "title": "Invert Regular Expression Matches with JavaScript",
      "description": [
        "You can invert any match by using the uppercase version of the regular expression selector.",
        "For example, <code>\\s</code> will match any whitespace, and <code>\\S</code> will match anything that isn't whitespace.",
        "Use <code>/\\S/g</code> to count the number of non-whitespace characters in <code>testString</code>."
      ],
      "tests": [
        "assert(editor.getValue().match(/\\/\\\\S\\/g/g), 'message: Use the <code>/\\S/g</code> regular expression to find non-space characters in <code>testString</code>.');",
        "assert(test === 49, 'message: Your regular expression should find forty nine non-space characters in the <code>testString</code>.');"
      ],
      "challengeSeed": [
        "var test = (function(){",
        "  var testString = \"How many non-space characters are there in this sentence?\";",
        "",
        "  // Only change code below this line.",
        "",
        "  var expression = /./g;",
        "",
        "  // Only change code above this line.",
        "",
        "  return testString.match(expression).length;",
        "})();(function(){return test;})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "cf1111c1c12feddfaeb9bdef",
      "title": "Create a JavaScript Slot Machine",
      "isBeta": true,
      "description": [
        "We are now going to try and combine some of the stuff we've just learned and create the logic for a slot machine game.",
        "For this we will need to generate three random numbers between <code>1</code> and <code>3</code> to represent the possible values of each individual slot.",
        "Store the three random numbers in <code>slotOne</code>, <code>slotTwo</code> and <code>slotThree</code>.",
        "Generate the random numbers by using the system we used earlier (an explanation of the formula can be found <a href=\"https://github.com/FreeCodeCamp/FreeCodeCamp/wiki/Waypoint-Generate-Random-Whole-Numbers-within-a-Range#explanation\">here</a>):",
        "<code>Math.floor(Math.random() * (3 - 1 + 1)) + 1;</code>"
      ],
      "tests": [
        "assert(typeof(runSlots($(\".slot\"))[0]) === \"number\" && runSlots($(\".slot\"))[0] > 0 && runSlots($(\".slot\"))[0] < 4, '<code>slotOne</code> should be a random number.')",
        "assert(typeof(runSlots($(\".slot\"))[1]) === \"number\" && runSlots($(\".slot\"))[1] > 0 && runSlots($(\".slot\"))[1] < 4, '<code>slotTwo</code> should be a random number.')",
        "assert(typeof(runSlots($(\".slot\"))[2]) === \"number\" && runSlots($(\".slot\"))[2] > 0 && runSlots($(\".slot\"))[2] < 4, '<code>slotThree</code> should be a random number.')",
        "assert((function(){if(editor.match(/Math\\.floor\\(\\s?Math\\.random\\(\\)\\s?\\*\\s?\\(\\s?3\\s?\\-\\s?1\\s?\\+\\s?1\\s?\\)\\s?\\)\\s?\\+\\s?1/gi) !== null){return editor.match(/slot.*?=.*?\\(.*?\\).*?/gi).length >= 3;}else{return false;}})(), 'You should have used <code>Math.floor(Math.random() * (3 - 1 + 1)) + 1;</code> three times to generate your random numbers.')"
      ],
      "challengeSeed": [
        "fccss",
        "  function runSlots() {",
        "    var slotOne;",
        "    var slotTwo;",
        "    var slotThree;",
        "   ",
        "    var images = [\"http://i.imgur.com/9H17QFk.png\", \"http://i.imgur.com/9RmpXTy.png\", \"http://i.imgur.com/VJnmtt5.png\"];",
        "   ",
        "    // Only change code below this line.",
        "    ",
        "    ",
        "    ",
        "    // Only change code above this line.",
        "    ",
        "    ",
        "    if (slotOne !== undefined && slotTwo !== undefined && slotThree !== undefined) {",
        "      $(\".logger\").html(slotOne + \" \" + slotTwo + \" \" + slotThree);",
        "    }",
        "    ",
        "    ",
        "    $(\".logger\").append(\" Not A Win\")",
        "    return [slotOne, slotTwo, slotThree];",
        "  }",
        "",
        "  $(document).ready(function() {",
        "     $(\".go\").click(function() {",
        "       runSlots();",
        "     });",
        "   });",
        "fcces",
        " ",
        "<div>",
        " <div class = \"container inset\">",
        "   <div class = \"header inset\">",
        "     <img src=\"https://s3.amazonaws.com/freecodecamp/freecodecamp_logo.svg.gz\" alt=\"learn to code javascript at Free Code Camp logo\" class=\"img-responsive nav-logo\">",
        "     <h2>FCC Slot Machine</h2>",
        "   </div>",
        "   <div class = \"slots inset\">",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "   </div>",
        "   <br/>",
        "   <div class = \"outset\">",
        "     <button class = \"go inset\">",
        "       Go",
        "     </button>",
        "   </div>",
        "   <br/>",
        "   <div class = \"foot inset\">",
        "     <span class = \"logger\"></span>",
        "   </div>",
        " </div>",
        "</div>",
        "",
        "<style>",
        " .container {",
        "   background-color: #4a2b0f;",
        "   height: 400px;",
        "   width: 260px;",
        "   margin: 50px auto;",
        "   border-radius: 4px;",
        " }",
        " .header {",
        "   border: 2px solid #fff;",
        "   border-radius: 4px;",
        "   height: 55px;",
        "   margin: 14px auto;",
        "   background-color: #457f86",
        " }",
        " .header h2 {",
        "   height: 30px;",
        "   margin: auto;",
        " }",
        " .header h2 {",
        "   font-size: 14px;",
        "   margin: 0 0;",
        "   padding: 0;",
        "   color: #fff;",
        "   text-align: center;",
        " }",
        " .slots{",
        "   display: flex;",
        "   background-color: #457f86;",
        "   border-radius: 6px;",
        "   border: 2px solid #fff;",
        " }",
        " .slot{",
        "   flex: 1 0 auto;",
        "   background: white;",
        "   height: 75px;",
        "   margin: 8px;",
        "   border: 2px solid #215f1e;",
        "   border-radius: 4px;",
        " }",
        " .go {",
        "   width: 100%;",
        "   color: #fff;",
        "   background-color: #457f86;",
        "   border: 2px solid #fff;",
        "   border-radius: 2px;",
        "   box-sizing: none;",
        "   outline: none!important;",
        " }",
        " .foot {",
        "   height: 150px;",
        "   background-color: 457f86;",
        "   border: 2px solid #fff;",
        " }",
        " ",
        " .logger {",
        "   color: white;",
        "   margin: 10px;",
        " }",
        " ",
        " .outset {",
        "   -webkit-box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   -moz-box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "     box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        " }",
        " ",
        " .inset {",
        "   -webkit-box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   -moz-box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        " }",
        "</style>"
      ],
      "type": "waypoint",
      "challengeType": 0
    },
    {
      "id": "cf1111c1c13feddfaeb1bdef",
      "title": "Add your JavaScript Slot Machine Slots",
      "isBeta": true,
      "description": [
        "Now that our slots will each generate random numbers, we need to check whether they've all returned the same number.",
        "If they have, we should notify our user that they've won and we should return <code>null</code>.",
        "<code>null</code> is a JavaScript data structure that means nothing.",
        "The user wins when all the three numbers match. Let's create an <code>if statement</code> with multiple conditions in order to check whether all numbers are equal.",
        "<code>if(slotOne === slotTwo && slotTwo === slotThree){</code>",
        "<code>&nbsp;&nbsp;return null;</code>",
        "<code>}</code>",
        "Also, we need to show the user that he has won the game when he gets the same number in all the slots.",
        "If all three numbers match, we should also set the text <code>\"It's A Win\"</code> to the element with class <code>logger</code>."
      ],
      "tests": [
        "assert((function(){var data = runSlots();return data === null || data.toString().length === 1;})(), 'If all three of our random numbers are the same we should return that number. Otherwise we should return <code>null</code>.')"
      ],
      "challengeSeed": [
        "fccss",
        "  function runSlots() {",
        "    var slotOne;",
        "    var slotTwo;",
        "    var slotThree;",
        "    ",
        "    var images = [\"http://i.imgur.com/9H17QFk.png\", \"http://i.imgur.com/9RmpXTy.png\", \"http://i.imgur.com/VJnmtt5.png\"];",
        "    ",
        "    slotOne = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    slotTwo = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    slotThree = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    ",
        "    ",
        "    // Only change code below this line.",
        "    ",
        "    ",
        "    ",
        "    // Only change code above this line.",
        "    ",
        "    if(slotOne !== undefined && slotTwo !== undefined && slotThree !== undefined){",
        "      $(\".logger\").html(slotOne + \" \" + slotTwo + \" \" + slotThree);",
        "    }",
        "    ",
        "    $(\".logger\").append(\" Not A Win\");",
        "    ",
        "    return [slotOne, slotTwo, slotThree];",
        "  }",
        "",
        "  $(document).ready(function() {",
        "     $(\".go\").click(function() {",
        "       runSlots();",
        "     });",
        "   });",
        "fcces",
        " ",
        "<div>",
        " <div class = \"container inset\">",
        "   <div class = \"header inset\">",
        "     <img src=\"https://s3.amazonaws.com/freecodecamp/freecodecamp_logo.svg.gz\" alt=\"learn to code javascript at Free Code Camp logo\" class=\"img-responsive nav-logo\">",
        "     <h2>FCC Slot Machine</h2>",
        "   </div>",
        "   <div class = \"slots inset\">",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "   </div>",
        "   <br/>",
        "   <div class = \"outset\">",
        "     <button class = \"go inset\">",
        "       Go",
        "     </button>",
        "   </div>",
        "   <br/>",
        "   <div class = \"foot inset\">",
        "     <span class = \"logger\"></span>",
        "   </div>",
        " </div>",
        "</div>",
        "",
        "<style>",
        " .container {",
        "   background-color: #4a2b0f;",
        "   height: 400px;",
        "   width: 260px;",
        "   margin: 50px auto;",
        "   border-radius: 4px;",
        " }",
        " .header {",
        "   border: 2px solid #fff;",
        "   border-radius: 4px;",
        "   height: 55px;",
        "   margin: 14px auto;",
        "   background-color: #457f86",
        " }",
        " .header h2 {",
        "   height: 30px;",
        "   margin: auto;",
        " }",
        " .header h2 {",
        "   font-size: 14px;",
        "   margin: 0 0;",
        "   padding: 0;",
        "   color: #fff;",
        "   text-align: center;",
        " }",
        " .slots{",
        "   display: flex;",
        "   background-color: #457f86;",
        "   border-radius: 6px;",
        "   border: 2px solid #fff;",
        " }",
        " .slot{",
        "   flex: 1 0 auto;",
        "   background: white;",
        "   height: 75px;",
        "   margin: 8px;",
        "   border: 2px solid #215f1e;",
        "   border-radius: 4px;",
        " }",
        " .go {",
        "   width: 100%;",
        "   color: #fff;",
        "   background-color: #457f86;",
        "   border: 2px solid #fff;",
        "   border-radius: 2px;",
        "   box-sizing: none;",
        "   outline: none!important;",
        " }",
        " .foot {",
        "   height: 150px;",
        "   background-color: 457f86;",
        "   border: 2px solid #fff;",
        " }",
        " ",
        " .logger {",
        "   color: white;",
        "   margin: 10px;",
        " }",
        " ",
        " .outset {",
        "   -webkit-box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   -moz-box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "     box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        " }",
        " ",
        " .inset {",
        "   -webkit-box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   -moz-box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        " }",
        "</style>"
      ],
      "type": "waypoint",
      "challengeType": 0
    },
    {
      "id": "cf1111c1c13feddfaeb2bdef",
      "title": "Bring your JavaScript Slot Machine to Life",
      "isBeta": true,
      "description": [
        "Now we can detect a win. Let's get this slot machine working.",
        "Let's use the jQuery <code>selector</code> <code>$(\".slot\")</code> to select all of the slots.",
        "Once they are all selected, we can use <code>bracket notation</code> to access each individual slot:",
        "<code>$($(\".slot\")[0]).html(slotOne);</code>",
        "This jQuery will select the first slot and update it's HTML to display the correct number.",
        "Use the above selector to display each number in its corresponding slot."
      ],
      "tests": [
        "assert((function(){runSlots();if($($(\".slot\")[0]).html().replace(/\\s/gi, \"\") !== \"\" && $($(\".slot\")[1]).html().replace(/\\s/gi, \"\") !== \"\" && $($(\".slot\")[2]).html().replace(/\\s/gi, \"\") !== \"\"){return true;}else{return false;}})(), 'You should be displaying the result of the slot numbers in the corresponding slots.')",
        "assert((editor.match( /\\$\\s*?\\(\\s*?\\$\\s*?\\(\\s*?(?:'|\")\\s*?\\.slot\\s*?(?:'|\")\\s*?\\)\\[\\d\\]\\s*?\\)/gi) && editor.match( /\\$\\s*?\\(\\s*?\\$\\s*?\\(\\s*?(?:'|\")\\s*?\\.slot\\s*?(?:'|\")\\s*?\\)\\[\\d\\]\\s*?\\)/gi ).length >= 3 && editor.match( /\\.html\\(slotOne\\)/gi ) && editor.match( /\\.html\\(slotTwo\\)/gi ) && editor.match( /\\.html\\(slotThree\\)/gi )), 'You should have used the the selector given in the description to select each slot and assign it the value of <code>slotOne</code>&#44; <code>slotTwo</code> and <code>slotThree</code> respectively.')"
      ],
      "challengeSeed": [
        "fccss",
        "  function runSlots() {",
        "    var slotOne;",
        "    var slotTwo;",
        "    var slotThree;",
        "    ",
        "    var images = [\"http://i.imgur.com/9H17QFk.png\", \"http://i.imgur.com/9RmpXTy.png\", \"http://i.imgur.com/VJnmtt5.png\"];",
        "    ",
        "    slotOne = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    slotTwo = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    slotThree = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    ",
        "    ",
        "    // Only change code below this line.",
        "    ",
        "    ",
        "    ",
        "    // Only change code above this line.",
        "    ",
        "    if (slotOne === slotTwo && slotTwo === slotThree) {",
        "      $(\".logger\").html(\" It's A Win\")",
        "      return null;",
        "    }",
        "    ",
        "    if(slotOne !== undefined && slotTwo !== undefined && slotThree !== undefined){",
        "      $(\".logger\").html(slotOne + \" \" + slotTwo + \" \" + slotThree);",
        "    }",
        "    ",
        "    $(\".logger\").append(\" Not A Win\");",
        "    ",
        "    ",
        "    return [slotOne, slotTwo, slotThree];",
        "  }",
        "",
        "  $(document).ready(function() {",
        "     $(\".go\").click(function() {",
        "       runSlots();",
        "     });",
        "   });",
        "fcces",
        " ",
        "<div>",
        " <div class = \"container inset\">",
        "   <div class = \"header inset\">",
        "     <img src=\"https://s3.amazonaws.com/freecodecamp/freecodecamp_logo.svg.gz\" alt=\"learn to code javascript at Free Code Camp logo\" class=\"img-responsive nav-logo\">",
        "     <h2>FCC Slot Machine</h2>",
        "   </div>",
        "   <div class = \"slots inset\">",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "     <div class = \"slot inset\">",
        "       ",
        "     </div>",
        "   </div>",
        "   <br/>",
        "   <div class = \"outset\">",
        "     <button class = \"go inset\">",
        "       Go",
        "     </button>",
        "   </div>",
        "   <br/>",
        "   <div class = \"foot inset\">",
        "     <span class = \"logger\"></span>",
        "   </div>",
        " </div>",
        "</div>",
        "",
        "<style>",
        " .container {",
        "   background-color: #4a2b0f;",
        "   height: 400px;",
        "   width: 260px;",
        "   margin: 50px auto;",
        "   border-radius: 4px;",
        " }",
        " .header {",
        "   border: 2px solid #fff;",
        "   border-radius: 4px;",
        "   height: 55px;",
        "   margin: 14px auto;",
        "   background-color: #457f86",
        " }",
        " .header h2 {",
        "   height: 30px;",
        "   margin: auto;",
        " }",
        " .header h2 {",
        "   font-size: 14px;",
        "   margin: 0 0;",
        "   padding: 0;",
        "   color: #fff;",
        "   text-align: center;",
        " }",
        " .slots{",
        "   display: flex;",
        "   background-color: #457f86;",
        "   border-radius: 6px;",
        "   border: 2px solid #fff;",
        " }",
        " .slot{",
        "   flex: 1 0 auto;",
        "   background: white;",
        "   height: 75px;",
        "   margin: 8px;",
        "   border: 2px solid #215f1e;",
        "   border-radius: 4px;",
        "   text-align: center;",
        "   padding-top: 25px;",
        " }",
        " .go {",
        "   width: 100%;",
        "   color: #fff;",
        "   background-color: #457f86;",
        "   border: 2px solid #fff;",
        "   border-radius: 2px;",
        "   box-sizing: none;",
        "   outline: none!important;",
        " }",
        " .foot {",
        "   height: 150px;",
        "   background-color: 457f86;",
        "   border: 2px solid #fff;",
        " }",
        " ",
        " .logger {",
        "   color: white;",
        "   margin: 10px;",
        " }",
        " ",
        " .outset {",
        "   -webkit-box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   -moz-box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "     box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        " }",
        " ",
        " .inset {",
        "   -webkit-box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   -moz-box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        " }",
        "</style>"
      ],
      "type": "waypoint",
      "challengeType": 0
    },
    {
      "id": "cf1111c1c11feddfaeb1bdff",
      "title": "Give your JavaScript Slot Machine some Stylish Images",
      "isBeta": true,
      "description": [
        "Now let's add some images to our slots.",
        "We've already set up the images for you in an array called <code>images</code>. We can use different indexes to grab each of these.",
        "Here's how we would set the first slot to show a different image depending on which number its random number generates:",
        "<code>$($('.slot')[0]).html('&lt;img src = \"' + images[slotOne-1] + '\"&gt;');</code>",
        "Set up all three slots like this, then click the \"Go\" button to play the slot machine."
      ],
      "tests": [
        "assert((editor.match(/\\$\\s*?\\(\\s*?\\$\\s*?\\(\\s*?(?:'|\")\\s*?\\.slot\\s*?(?:'|\")\\s*?\\)\\[\\d\\]\\s*?\\)\\.html\\(\\s*?\\'\\<img\\s?src\\s?=\\s?\"\\'\\s?\\+\\s?images\\[\\w+\\s*\\-\\s*1\\]\\s?\\+\\s?\\'\"\\>\\'\\s*?\\);/gi) && editor.match(/\\$\\s*?\\(\\s*?\\$\\s*?\\(\\s*?(?:'|\")\\s*?\\.slot\\s*?(?:'|\")\\s*?\\)\\[\\d\\]\\s*?\\)\\.html\\(\\s*?\\'\\<img\\s?src\\s?=\\s?\"\\'\\s?\\+\\s?images\\[\\w+\\s*\\-\\s*1\\]\\s?\\+\\s?\\'\"\\>\\'\\s*?\\);/gi).length >= 3), 'Use the provided code three times. One for each slot.')",
        "assert(editor.match(/\\$\\s*?\\(\\s*?\\$\\s*?\\(\\s*?(?:'|\")\\s*?\\.slot\\s*?(?:'|\")\\s*?\\)\\[0\\]\\s*?\\)/gi), 'You should have used <code>$&#40;&#39;.slot&#39;&#41;[0]</code> at least once.')",
        "assert(editor.match(/\\$\\s*?\\(\\s*?\\$\\s*?\\(\\s*?(?:'|\")\\s*?\\.slot\\s*?(?:'|\")\\s*?\\)\\[1\\]\\s*?\\)/gi), 'You should have used <code>$&#40;&#39;.slot&#39;&#41;[1]</code> at least once.')",
        "assert(editor.match(/\\$\\s*?\\(\\s*?\\$\\s*?\\(\\s*?(?:'|\")\\s*?\\.slot\\s*?(?:'|\")\\s*?\\)\\[2\\]\\s*?\\)/gi), 'You should have used <code>$&#40;&#39;.slot&#39;&#41;[2]</code> at least once.')",
        "assert(editor.match(/slotOne/gi) && editor.match(/slotOne/gi).length >= 7, 'You should have used the <code>slotOne</code> value at least once.')",
        "assert(editor.match(/slotTwo/gi) && editor.match(/slotTwo/gi).length >= 8, 'You should have used the <code>slotTwo</code> value at least once.')",
        "assert(editor.match(/slotThree/gi) && editor.match(/slotThree/gi).length >= 7, 'You should have used the <code>slotThree</code> value at least once.')"
      ],
      "challengeSeed": [
        "fccss",
        "  function runSlots() {",
        "    var slotOne;",
        "    var slotTwo;",
        "    var slotThree;",
        "    ",
        "    var images = [\"http://i.imgur.com/9H17QFk.png\", \"http://i.imgur.com/9RmpXTy.png\", \"http://i.imgur.com/VJnmtt5.png\"];",
        "    ",
        "    slotOne = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    slotTwo = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    slotThree = Math.floor(Math.random() * (3 - 1 + 1)) + 1;",
        "    ",
        "    ",
        "    // Only change code below this line.",
        "    ",
        "    ",
        "    ",
        "    // Only change code above this line.",
        "    ",
        "    if (slotOne === slotTwo && slotTwo === slotThree) {",
        "      $('.logger').html(\"It's A Win\");",
        "      return null;",
        "    }",
        "    ",
        "    if(slotOne !== undefined && slotTwo !== undefined && slotThree !== undefined){",
        "      $(\".logger\").html(slotOne + \" \" + slotTwo + \" \" + slotThree);",
        "    }",
        "    ",
        "    $('.logger').append(\" Not A Win\");",
        "    ",
        "    return [slotOne, slotTwo, slotThree];",
        "  }",
        "",
        "  $(document).ready(function() {",
        "     $('.go').click(function() {",
        "       runSlots();",
        "     });",
        "   });",
        "fcces",
        " ",
        "<div>",
        " <div class = 'container inset'>",
        "   <div class = 'header inset'>",
        "     <img src='https://s3.amazonaws.com/freecodecamp/freecodecamp_logo.svg.gz' alt='learn to code javascript at Free Code Camp logo' class='img-responsive nav-logo'>",
        "     <h2>FCC Slot Machine</h2>",
        "   </div>",
        "   <div class = 'slots inset'>",
        "     <div class = 'slot inset'>",
        "       ",
        "     </div>",
        "     <div class = 'slot inset'>",
        "       ",
        "     </div>",
        "     <div class = 'slot inset'>",
        "       ",
        "     </div>",
        "   </div>",
        "   <br/>",
        "   <div class = 'outset'>",
        "     <button class = 'go inset'>",
        "       Go",
        "     </button>",
        "   </div>",
        "   <br/>",
        "   <div class = 'foot inset'>",
        "     <span class = 'logger'></span>",
        "   </div>",
        " </div>",
        "</div>",
        "",
        "<style>",
        " .slot > img {",
        "  margin: 0!important;",
        "  height: 71px;",
        "  width: 50px;",
        " }",
        " .container {",
        "   background-color: #4a2b0f;",
        "   height: 400px;",
        "   width: 260px;",
        "   margin: 50px auto;",
        "   border-radius: 4px;",
        " }",
        " .header {",
        "   border: 2px solid #fff;",
        "   border-radius: 4px;",
        "   height: 55px;",
        "   margin: 14px auto;",
        "   background-color: #457f86",
        " }",
        " .header h2 {",
        "   height: 30px;",
        "   margin: auto;",
        " }",
        " .header h2 {",
        "   font-size: 14px;",
        "   margin: 0 0;",
        "   padding: 0;",
        "   color: #fff;",
        "   text-align: center;",
        " }",
        " .slots{",
        "   display: flex;",
        "   background-color: #457f86;",
        "   border-radius: 6px;",
        "   border: 2px solid #fff;",
        " }",
        " .slot{",
        "   flex: 1 0 auto;",
        "   background: white;",
        "   height: 75px;",
        "   width: 50px;",
        "   margin: 8px;",
        "   border: 2px solid #215f1e;",
        "   border-radius: 4px;",
        "   text-align: center;",
        " }",
        " .go {",
        "   width: 100%;",
        "   color: #fff;",
        "   background-color: #457f86;",
        "   border: 2px solid #fff;",
        "   border-radius: 2px;",
        "   box-sizing: none;",
        "   outline: none!important;",
        " }",
        " .foot {",
        "   height: 150px;",
        "   background-color: 457f86;",
        "   border: 2px solid #fff;",
        " }",
        " ",
        " .logger {",
        "   color: white;",
        "   margin: 10px;",
        " }",
        " ",
        " .outset {",
        "   -webkit-box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   -moz-box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "     box-shadow: 0px 0px 15px -2px rgba(0,0,0,0.75);",
        " }",
        " ",
        " .inset {",
        "   -webkit-box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   -moz-box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        "   box-shadow: inset 0px 0px 15px -2px rgba(0,0,0,0.75);",
        " }",
        "</style>"
      ],
      "type": "waypoint",
      "challengeType": 0
    }
  ]
}