Files
Kristofer Koishigawa bcc9beff1f feat(curriculum): introduce let and const earlier (#43133)
* fix: move "Explore Differences Between..." to basic JS, update seed and tests

* fix: resequence "Declare String Variables"

* fix: move "Declare a Read-Only Variable..." to basic JS, update seed and tests

* fix: revert changes to non-English "Explore Differences Between..." test text

* fix: revert test strings, solutions, and seeds for non-English challenges

* fix: update "Declare String Variables" description

* fix: sync quotation marks in description and seed

* fix: modify note in "Declare a Read-Only..." challenge

* fix: update operator and compound assignment challenges

* fix: update string challenges

* fix: update array and array method challenges

* fix: update function and scope challenges, resequence slightly

* fix: "Word Blanks" solution

* fix: add spacing to seed

* fix: concatenating += challenge spacing

* fix: appending variables to strings spacing

* fix: find the length of a string spacing

* fix: removed instances of removedFromMyArray = 0

* fix: switch challenges

* fix: function argument and param spacing

* fix: update counting cards, object challenges, and record collection

* fix: finish rest of Basic JS section

* fix: introducing else statements solution

* fix: update spacing and wording

* fix: update wording for const challenge

* fix: update functional programming challenges

* fix: intermediate algorithms and cert challenges

* fix: revert some spacing and remove comments for fp challenge solutions

* feat: add notes with links to moved let and const challenges in first two es6 challenges

* fix: update es6 intro text

* Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/concatenating-strings-with-the-plus-equals-operator.md

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/finding-a-remainder-in-javascript.md

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/global-scope-and-functions.md

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/iterate-through-an-array-with-a-for-loop.md

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/iterate-through-an-array-with-a-for-loop.md

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/functional-programming/implement-map-on-a-prototype.md

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/declare-a-read-only-variable-with-the-const-keyword.md

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* fix: concatenating strings with plus operator seed

* fix: add comments back to Declare a Read-Only Variable... seed

* feat: add es6 to basic javascript redirect tests for let and const challenges

* fix: revert "Concatenating Strings with Plus Operator" seed

* fix: move test file to cypress/integration/learn/redirects, separate redirect tests

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>
2021-10-25 17:55:58 +01:00

1.9 KiB

id, title, challengeType, videoUrl, forumTopicId, dashedName
id title challengeType videoUrl forumTopicId dashedName
5675e877dbd60be8ad28edc6 Iterate Through an Array with a For Loop 1 https://scrimba.com/c/caeR3HB 18216 iterate-through-an-array-with-a-for-loop

--description--

A common task in JavaScript is to iterate through the contents of an array. One way to do that is with a for loop. This code will output each element of the array arr to the console:

const arr = [10, 9, 8, 7, 6];

for (let i = 0; i < arr.length; i++) {
   console.log(arr[i]);
}

Remember that arrays have zero-based indexing, which means the last index of the array is length - 1. Our condition for this loop is i < arr.length, which stops the loop when i is equal to length. In this case the last iteration is i === 4 i.e. when i becomes equal to arr.length - 1 and outputs 6 to the console. Then i increases to 5, and the loop terminates because i < arr.length is false.

--instructions--

Declare and initialize a variable total to 0. Use a for loop to add the value of each element of the myArr array to total.

--hints--

total should be declared and initialized to 0.

assert(code.match(/(var|let|const)\s*?total\s*=\s*0.*?;?/));

total should equal 20.

assert(total === 20);

You should use a for loop to iterate through myArr.

assert(/for\s*\(/g.test(code) && /myArr\s*\[/g.test(code));

You should not attempt to directly assign the value 20 to total.

assert(!__helpers.removeWhiteSpace(code).match(/total[=+-]0*[1-9]+/gm));

--seed--

--after-user-code--

(function(){if(typeof total !== 'undefined') { return "total = " + total; } else { return "total is undefined";}})()

--seed-contents--

// Setup
const myArr = [2, 3, 4, 5, 6];

// Only change code below this line

--solutions--

const myArr = [2, 3, 4, 5, 6];
let total = 0;

for (let i = 0; i < myArr.length; i++) {
  total += myArr[i];
}