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freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md
Kristofer Koishigawa bcc9beff1f feat(curriculum): introduce let and const earlier (#43133)
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* fix: concatenating strings with plus operator seed

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1.9 KiB

id, title, challengeType, videoUrl, forumTopicId, dashedName
id title challengeType videoUrl forumTopicId dashedName
56bbb991ad1ed5201cd392ca Access Array Data with Indexes 1 https://scrimba.com/c/cBZQbTz 16158 access-array-data-with-indexes

--description--

We can access the data inside arrays using indexes.

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. Like strings, arrays use zero-based indexing, so the first element in an array has an index of 0.


Example

const array = [50, 60, 70];
array[0];
const data = array[1];

array[0] is now 50, and data has the value 60.

Note: There shouldn't be any spaces between the array name and the square brackets, like array [0]. Although JavaScript is able to process this correctly, this may confuse other programmers reading your code.

--instructions--

Create a variable called myData and set it to equal the first value of myArray using bracket notation.

--hints--

The variable myData should equal the first value of myArray.

assert(
  (function () {
    if (
      typeof myArray !== 'undefined' &&
      typeof myData !== 'undefined' &&
      myArray[0] === myData
    ) {
      return true;
    } else {
      return false;
    }
  })()
);

The data in variable myArray should be accessed using bracket notation.

assert(
  (function () {
    if (code.match(/\s*=\s*myArray\[0\]/g)) {
      return true;
    } else {
      return false;
    }
  })()
);

--seed--

--after-user-code--

if(typeof myArray !== "undefined" && typeof myData !== "undefined"){(function(y,z){return 'myArray = ' + JSON.stringify(y) + ', myData = ' + JSON.stringify(z);})(myArray, myData);}

--seed-contents--

const myArray = [50, 60, 70];


--solutions--

const myArray = [50, 60, 70];
const myData = myArray[0];