freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/modify-array-data-with-indexes.english.md

id, title, challengeType

id	title	challengeType
cf1111c1c11feddfaeb8bdef	Modify Array Data With Indexes	1

Description

Unlike strings, the entries of arrays are mutable and can be changed freely. Example

var ourArray = [50,40,30];
ourArray[0] = 15; // equals [15,40,30]

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

Modify the data stored at index 0 of myArray to a value of 45.

Tests

tests:
  - text: '<code>myArray</code> should now be [45,64,99].'
    testString: 'assert((function(){if(typeof myArray != "undefined" && myArray[0] == 45 && myArray[1] == 64 && myArray[2] == 99){return true;}else{return false;}})(), "<code>myArray</code> should now be [45,64,99].");'
  - text: You should be using correct index to modify the value in <code>myArray</code>.
    testString: 'assert((function(){if(code.match(/myArray\[0\]\s*=\s*/g)){return true;}else{return false;}})(), "You should be using correct index to modify the value in <code>myArray</code>.");'

Challenge Seed

// Example
var ourArray = [18,64,99];
ourArray[1] = 45; // ourArray now equals [18,45,99].

// Setup
var myArray = [18,64,99];

// Only change code below this line.

After Test

console.info('after the test');

Solution

var myArray = [18,64,99];
myArray[0] = 45;