freeCodeCamp/seed/challenges/basic-javascript.json

{
  "name": "Basic JavaScript",
  "order": 6,
  "time": "3h",
  "challenges": [
    {
      "id":"bd7123c9c441eddfaeb4bdef",
      "title": "Comment your JavaScript Code",
      "difficulty":"9.98",
      "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 it 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.",
        "And one more thing you need to notice. Starting at this waypoint in JavaScript related challenges (except AngularJS, all Ziplines, Git, Node.js and Express.js, MongoDB and Full Stack JavaScript Projects) you can see contents of <code>assert()</code> functions (in some challenges <code>except()</code>, <code>assert.equal()</code> and so on) which are used to test your code. It's part of these challenges that you are able to see the tests that are running against your code."
      ],
      "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.",
        "}",
        "",
        "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\";",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "",
        "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 name = \"Alan Turing\";",
        "// var firstName = \"Alan\";",
        "// var lastName = \"Turing\";",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "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.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "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>firstLetterOfLastName</code> variable.",
        "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 first letter of <code>firstLetterOfLastName</code> should be a <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.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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 third letter of <code>lastName</code> should be a \"v\".');"
      ],
      "challengeSeed": [
        "var firstName = \"Ada\";",
        "",
        "var secondLetterOfFirstName = firstName[1];",
        "",
        "var lastName = \"Lovelace\";",
        "",
        "var thirdLetterOfLastName = lastName;",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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": [
        "In order to get the last letter of a string, you can subtract one from the string's length.",
        "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.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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.",
        "Replace the <code>0</code> with the correct number so you can get the result mentioned in the comment."
      ],
      "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; //make this equal to 20 by changing the 0 into the appropriate number.",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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.",
        "Replace the <code>0</code> with the correct number so you can get the result mentioned in the comment."
      ],
      "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; //make this equal to 12 by changing the 0 into the appropriate number.",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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.",
        "Replace the <code>0</code> with the correct number so you can get the result mentioned in the comment."
      ],
      "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; // Make this equal to 80 by changing the 0 into the appropriate number.",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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.",
        "Replace the <code>0</code> with the correct number so you can get the result mentioned in the comment."
      ],
      "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; //make this equal to 2 by changing the 0 into the appropriate number.",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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;",
        "// Create a number with a decimal point here called myDecimal",
        "",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(function(){if(typeof(myDecimal) !== \"undefined\"){return myDecimal;}})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bd7993c9c69feddfaeb7bdef",
      "title": "Perform Arithmetic Operations on Decimals with JavaScript",
      "description": [
        "In JavaScript, you can also perform calculations with decimal numbers, just like whole numbers.",
        "Replace the <code>0.0</code> with the correct number so that you get the result mentioned in the comments."
      ],
      "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.');",
        "assert((function(){if(quotient === 2.2 && editor.getValue().match(/\\//g)){return true;}else{return false;}})(), 'message: Make the variable <code>quotient</code> equal 2.2.');"
      ],
      "challengeSeed": [
        "var quotient = 4.4 / 2.0; // equals 2.2",
        "var product = 2.0 * 0.0; // equals 5.0",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(function(y){return 'product='+y;})(product);"
      ],
      "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.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(function(z){return z;})(myArray);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c11feddfaeb7bdef",
      "title": "Nest one Array within Another Array",
      "difficulty":"9.98161",
      "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.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"bg9997c9c79feddfaeb9bdef",
      "title": "Access Array Data with Indexes",
      "difficulty":"9.9817",
      "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.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "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",
      "difficulty":"9.98171",
      "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.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "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 retrieve this value by performing <code>pop()</code> in a variable declaration.",
        "Any type of variable can be \"popped\" off of an array.",
        "Use the <code>.pop()</code> function to remove the last item from <code>myArray</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;}})(removed), 'message: <code>removed</code> should only contain <code>[\"cat\", 2]</code>.');"
      ],
      "challengeSeed": [
        "// var numbers = [1,2,3];",
        "// console.log(numbers); // logs [1,2,3]",
        "// var removed = numbers.pop();",
        "// console.log(numbers); // logs [1,2]",
        "// console.log(removed); // logs 3",
        "",
        "var myArray = [\"John\", 23, [\"cat\", 2]];",
        "// Only change code below this line.",
        "",
        "var removed = myArray; // This should be [\"cat\", 2] and myArray should now be [\"John\", 23]",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(function(y, z){return 'myArray = ' + JSON.stringify(y) + ' & removed = ' + JSON.stringify(z);})(myArray, removed);"
      ],
      "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.",
        "Take the <code>myArray</code> array and <code>push()</code> this value to the end of it: <code>[\"dog\", 3]</code>."
      ],
      "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.push([\"happy\", \"joy\"]);",
        "// ourArray now equals [\"Stimpson\", \"J\", [\"happy\", \"joy\"]].",
        "",
        "var myArray = [\"John\", 23, [\"cat\", 2]];",
        "myArray.pop();",
        "// Add a [\"dog\", 3] to the end of myArray using push().",
        "// Only change code below this line.",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(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.",
        "Take the <code>myArray</code> array and <code>shift()</code> the first value off of it. Set <code>myRemoved</code> to the first value of <code>myArray</code> using <code>shift()</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(myRemoved) === 'string'){return true;}else{return false;}})(myRemoved), 'message: <code>myRemoved</code> should contain <code>\"John\"</code>.');"
      ],
      "challengeSeed": [
        "var ourArray = [\"Stimpson\", \"J\", [\"cat\"]];",
        "ourRemoved = ourArray.shift();",
        "// ourArray now equals [\"J\", [\"cat\"]].",
        "",
        "var myArray = [\"John\", 23, [\"dog\", 3]];",
        "// Only change code below this line.",
        "",
        "var myRemoved = myArray; // This should be [\"John\"] and myArray should now be [23, [\"dog\", 3]].",
        "",
        "// Only change code above this line.",
        "",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(function(y, z){return 'myArray = ' + JSON.stringify(y) + ' & myRemoved = ' + JSON.stringify(z);})(myArray, myRemoved);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id": "bg9997c9c69feddfaeb9bdef",
      "title": "Manipulate Arrays With unshift()",
      "description": [
        "Now that we've learned how to <code>shift</code>things from the start of the array, we need to learn how to <code>unshift</code>stuff back to the start.",
        "Let's take the code we had last time and <code>unshift</code>this value to the start: <code>\"Paul\"</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();",
        "",
        "// Add \"Paul\" to the start of myArray.",
        "// Only change code below this line.",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "(function(y, z){return 'myArray = ' + JSON.stringify(y);})(myArray);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"bg9997c9c89feddfaeb9bdef",
      "title": "Write Reusable JavaScript with Functions",
      "difficulty":"9.9819",
      "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>&thinsp;&thinsp;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 a + b');"
      ],
      "challengeSeed":[
        "var a = 4;",
        "var b = 5;",
        "",
        "function ourFunction(a, b) {",
        "  return a - b;",
        "}",
        "",
        "// Create a function called myFunction that returns the value of a plus b.",
        "// Only change code below this line.",
        "",
        "",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "if(typeof(myFunction) !== \"undefined\"){",
        "var f=myFunction(a,b);",
        "(function(){return f;})();",
        "}"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"bg9998c9c99feddfaeb9bdef",
      "title": "Build JavaScript Objects",
      "difficulty":"9.9822",
      "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>  \"name\": \"Whiskers\",</code>",
        "<code>  \"legs\": 4,</code>",
        "<code>  \"tails\": 1,</code>",
        "<code>  \"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> (String), <code>'legs'</code> (Number), <code>'tails'</code> (Number) and <code>'friends'</code> (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!\"]",
        "// };",
        "",
        "// Add the name (string), legs (number), tails (number) and friends (array) properties to myDog.",
        "// You can set them to whatever you want.",
        "",
        "// Only change code below this line.",
        "",
        "var myDog = {",
        "   ",
        "};",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "(function(z){return z;})(myDog);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"bg9999c9c99feddfaeb9bdef",
      "title": "Manipulate JavaScript Objects",
      "difficulty":"9.9823",
      "description":[
        "There are many ways to add and remove properties from objects.",
        "For example, we can add properties to objects like this:",
        "<code>myObject.myProperty = \"myValue\";</code>",
        "We can also delete them like this:",
        "<code>delete myObject.myProperty;</code>",
        "Let's add the property <code>\"bark\"</code>, and delete the property <code>\"tails\"</code>."
      ],
      "tests":[
        "assert(myDog.bark !== undefined, 'message: Add the property <code>\"bark\"</code> to <code>myDog</code>.');",
        "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!\"]",
        "// };",
        "",
        "// ourDog.bark = \"arf!\";",
        "// delete ourDog.tails;",
        "",
        "var myDog = {",
        "   \"name\": \"Camper\",",
        "   \"legs\": 4,",
        "   \"tails\": 1,",
        "   \"friends\": []",
        "};",
        "",
        "// Only change code below this line.",
        "",
        "// Let's add the property bark to myDog",
        "",
        "",
        "// Now delete the property tails",
        "",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "(function(z){return z;})(myDog);"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c11feddfaeb5bdef",
      "title": "Iterate with JavaScript For Loops",
      "difficulty":"9.9824",
      "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.",
        "<code>var ourArray = [];</code>",
        "<code>for(var i = 0; i < 5; i++) {</code>",
        "<code>&thinsp;&thinsp;ourArray.push(i);</code>",
        "<code>}</code>",
        "<code>ourArray</code> will now contain [0,1,2,3,4] ",
        "Let's try getting a for loop to work by pushing values to an array."
      ],
      "tests":[
        "assert(editor.getValue().match(/for/g), 'message: You should be using a <code>for</code> loop for this.');",
        "assert.deepEqual(myArray, [0,1,2,3,4], 'message: <code>myArray</code> should equal [0,1,2,3,4].');"
      ],
      "challengeSeed":[
        "var ourArray = [];",
        "for(var i = 0; i < 5; i++){",
        "  ourArray.push(i);",
        "}",
        "var myArray = [];",
        "",
        "// Only change code below this line.",
        "",
        "// Push the numbers zero through four to myArray using a \"for loop\" like above.",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}",
        ""
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c11feddfaeb1bdef",
      "title": "Iterate with JavaScript While Loops",
      "difficulty":"9.9825",
      "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>&thinsp;&thinsp;ourArray.push(i);</code>",
        "<code>&thinsp;&thinsp;i++;</code>",
        "<code>}</code>",
        "Let's try getting a while loop to work by pushing values to an array."
      ],
      "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 [0,1,2,3,4].');"
      ],
      "challengeSeed":[
        "var myArray = [];",
        "// Only change code below this line.",
        "",
        "// Push the numbers zero through four to myArray using a \"while loop\".",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "// You'll learn about functions soon.",
        "if(typeof(myArray) !== \"undefined\"){(function(){return myArray;})();}",
        ""
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c11feddfaeb9bdef",
      "title": "Generate Random Fractions with JavaScript",
      "difficulty":"9.9827",
      "description":[
        "Random numbers are useful for creating random behavior.",
        "JavaScript has a <code>Math.random()</code> function that generates a random decimal number.",
        "Use <code>Math.random()</code> to get <code>myFunction</code> to return a random number."
      ],
      "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 >= 2, 'message: You should be using <code>Math.random</code> to generate the random decimal number.');"
      ],
      "challengeSeed":[
        "function myFunction() {",
        "  // Change the 0 to Math.random().",
        "  // Only change code below this line.",
        "",
        "  return 0;",
        "",
        "  // Only change code above this line.",
        "}",
        "",
        "// We use this function to show you the value of your variable in your output box.",
        "(function(){return myFunction();})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c12feddfaeb1bdef",
      "title": "Generate Random Whole Numbers with JavaScript",
      "difficulty":"9.9828",
      "description":[
        "It's great that we can create random decimal numbers, but it's even more useful if we use it to generate a random whole number.",
        "To achieve this we can multiply the random number by ten and use the <code>Math.floor()</code> to convert the decimal number to the nearest less than or equal whole number.",
        "This technique gives us a whole number between zero and nine.",
        "Example:",
        "<code>Math.floor(Math.random()*10);</code>",
        "Let's give this technique a go now."
      ],
      "tests":[
        "assert(typeof(myFunction()) === \"number\", 'message: The result of <code>myFunction</code> should be a number.');",
        "assert(editor.getValue().match(/Math.random/g), 'message: You should be using Math.random to create 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), 'message: You should use <code>Math.floor</code> to remove the decimal part of the number.');"
      ],
      "challengeSeed":[
        "function myFunction(){",
        "  // Make myFunction return a random number between zero and nine instead of a decimal.",
        "",
        "  // Only change code below this line.",
        "",
        "  return Math.random();",
        "",
        "  // Only change code above this line.",
        "}",
        "",
        "// We use this function to show you the value of your variable in your output box.",
        "(function(){return myFunction();})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c12feddfaeb2bdef",
      "title": "Generate Random Whole Numbers within a Range",
      "difficulty":"9.9829",
      "description":[
        "We can use a certain mathematical expression to get a random number between two numbers.",
        "<code>Math.floor(Math.random() * (max - min + 1)) + min</code>",
        "By using this, we can control the output of a random number."
      ],
      "tests":[
        "assert(myFunction() >= min, 'message: The random number generated by <code>myFunction</code> should be greater than or equal to the minimum number.');",
        "assert(myFunction() <= max, 'message: The random number generated by <code>myFunction</code> should be less than or equal to the maximum number.');",
        "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(/max/g).length >= 3 && editor.getValue().match(/min/g).length >= 4 && editor.getValue().match(/Math.floor/g) && editor.getValue().match(/Math.random/g)){return true;}else{return false;}})(), 'message: You should be using the function given in the description to calculate the random in number in a range.');"
      ],
      "challengeSeed":[
        "var min = 1;",
        "var max = 9;",
        "function myFunction() {",
        "  // Make myFunction return a random number between min and max values instead of a decimal",
        "  // Only change code below this line.",
        "",
        "  return Math.random();",
        "}",
        "",
        "// Only change code above this line.",
        "// We use this function to show you the value of your variable in your output box.",
        "(function(){return myFunction();})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c12feddfaeb3bdef",
      "title": "Use Conditional Logic with If and Else Statements",
      "difficulty":"9.983",
      "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> if (1 === 2) {</code>",
        "<code>&thinsp;&thinsp;return true;</code>",
        "<code>} else {</code>",
        "<code>&thinsp;&thinsp;return false;</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((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.');",
        "assert(editor.getValue().match(/if/g).length >= 4, 'message: You should have created a new if statement.');",
        "assert(editor.getValue().match(/else/g).length >= 2, 'message: You should have created a new else statement.');"
      ],
      "challengeSeed":[
        "var flip = Math.floor(Math.random() * (1 - 0 + 1)) + 0;",
        "function myFunction(){",
        "  // Create an if-else statement here to return \"heads\" if flip is 0. Otherwise return \"tails\".",
        "",
        "  // Only change code below this line.",
        "",
        "",
        "",
        "  // Only change code above this line.",
        "}",
        "",
        "// We use this function to show you the value of your variable in your output box.",
        "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",
      "difficulty":"9.984",
      "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 current <code>regular expression</code> 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: You should have used <code>regular expressions</code> to find the word <code>and</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.",
        "  // We use this function to show you the value of your variable in your output box.",
        "  return testString.match(expression).length;",
        "})();(function(){return test;})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c12feddfaeb7bdef",
      "title": "Find Numbers with Regular Expressions",
      "difficulty":"9.985",
      "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 grab 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(test === 2, 'message: Your RegEx should have found two numbers in the <code>testString</code>.');",
        "assert(editor.getValue().match(/\\/\\\\d\\+\\//g), 'message: You should be using the following expression <code>/\\d+/g</code> to find the numbers in the <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.",
        "  // We use this function to show you the value of your variable in your output box.",
        "  return testString.match(expression).length;",
        "})();(function(){return test;})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c12feddfaeb8bdef",
      "title": "Find Whitespace with Regular Expressions",
      "difficulty":"9.986",
      "description":[
        "We can also use selectors like <code>\\s</code> to find whitespace in a string.",
        "The whitespace characters are <code>\" \"</code> (space), <code>\\r</code> (carriage return), <code>\\n</code> (newline), <code>\\t</code> (tab), and <code>\\f</code> (form feed).",
        "It is used like this:",
        "<code>/\\s+/g</code>",
        "Select all the whitespace characters in the sentence string."
      ],
      "tests":[
        "assert(test === 7, 'message: Your RegEx should have found seven spaces in the <code>testString</code>.');",
        "assert(editor.getValue().match(/\\/\\\\s\\+\\//g), 'message: You should be using the following expression <code>/\\s+/g</code> to find the spaces in the <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.",
        "  // We use this function to show you the value of your variable in your output box.",
        "  return testString.match(expression).length;",
        "})();(function(){return test;})();"
      ],
      "type": "waypoint",
      "challengeType": 1
    },
    {
      "id":"cf1111c1c13feddfaeb3bdef",
      "title": "Invert Regular Expression Matches with JavaScript",
      "difficulty":"9.987",
      "description":[
        "Use <code>/\\S/g</code> to match everything that isn't a space in the string.",
        "You can invert any match by using the uppercase version of the selector <code>\\s</code> versus <code>\\S</code> for example."
      ],
      "tests":[
        "assert(test === 49, 'message: Your RegEx should have found forty nine non-space characters in the <code>testString</code>.');",
        "assert(editor.getValue().match(/\\/\\\\S\\/g/g), 'message: You should be using the following expression <code>/\\S/g</code> to find 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.",
        "  // We use this function to show you the value of your variable in your output box.",
        "  return testString.match(expression).length;",
        "})();(function(){return test;})();"
      ],
      "type": "waypoint",
      "challengeType":1
    },
    {
      "id":"cf1111c1c12feddfaeb9bdef",
      "title": "Create a JavaScript Slot Machine",
      "difficulty":"9.988",
      "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($(\".slot\"))[0]) === \"number\", '<code>slotOne</code> should be a random number.')",
        "assert(typeof(runSlots($(\".slot\"))[1]) === \"number\", '<code>slotTwo</code> should be a random number.')",
        "assert(typeof(runSlots($(\".slot\"))[2]) === \"number\", '<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(/Math\\.floor\\(\\s?Math\\.random\\(\\)\\s?\\*\\s?\\(\\s?3\\s?\\-\\s?1\\s?\\+\\s?1\\s?\\)\\s?\\)\\s?\\+\\s?1;/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.",
        "    ",
        "    $(\".logger\").html(\"\");",
        "    $(\".logger\").html(\"Not A Win\")",
        "    ",
        "    if(slotOne !== undefined && slotTwo !== undefined && slotThree !== undefined){",
        "      $(\".logger\").html(slotOne + \" \" + slotTwo + \" \" + slotThree);",
        "    }",
        "    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",
      "difficulty":"9.989",
      "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.",
        "Otherwise, we should return <code>null</code>, which is a JavaScript data structure that means nothing.",
        "If all three numbers match, we should return the number that we have in three of slots or leave it as <code>null</code>.",
        "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>&thinsp;&thinsp;return null;</code>",
        "<code>}</code>"
      ],
      "tests":[
        "assert((function(){var data = runSlots();if(data === null){return true}else{if(data[0] === data[1] && data[1] === data[2]){return true;}else{return false;}}})(), '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;",
        "    ",
        "    $(\".logger\").html(\"\");",
        "    $(\".logger\").html(\"Not A Win\")",
        "    ",
        "    // Only change code below this line.",
        "    ",
        "    ",
        "    ",
        "    // Only change code above this line.",
        "    ",
        "    if(slotOne !== undefined && slotTwo !== undefined && slotThree !== undefined){",
        "      $(\".logger\").html(slotOne);",
        "      $(\".logger\").append(\" \" + slotTwo);",
        "      $(\".logger\").append(\" \" + slotThree);",
        "    }",
        "    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",
      "difficulty":"9.990",
      "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 and update the slot'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;",
        "    ",
        "    $(\".logger\").html(\"\");",
        "    $(\".logger\").html(\"Not A Win\")",
        "    ",
        "    // Only change code below this line.",
        "    ",
        "    ",
        "    ",
        "    // Only change code above this line.",
        "    ",
        "    if(slotOne !== slotTwo || slotTwo !== slotThree){",
        "      return null;",
        "    }",
        "    ",
        "    if(slotOne !== undefined && slotTwo !== undefined && slotThree !== undefined){",
        "      $(\".logger\").html(slotOne);",
        "      $(\".logger\").append(\" \" + slotTwo);",
        "      $(\".logger\").append(\" \" + slotThree);",
        "    }",
        "    ",
        "    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",
      "difficulty":"9.9901",
      "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+\\-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+\\-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;",
        "    ",
        "    $('.logger').html('');",
        "    $('.logger').html('Not A Win');",
        "    ",
        "    // Only change code below this line.",
        "    ",
        "    ",
        "    ",
        "    // Only change code above this line.",
        "    ",
        "    if(slotOne !== slotTwo || slotTwo !== slotThree){",
        "      return null;",
        "    }",
        "    ",
        "    if(slotOne !== undefined && slotTwo !== undefined && slotThree !== undefined){",
        "      $('.logger').html(slotOne);",
        "      $('.logger').append(' ' + slotTwo);",
        "      $('.logger').append(' ' + slotThree);",
        "    }",
        "    ",
        "    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
    }
  ]
}