freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-an.../basic-javascript/access-multi-dimensional-ar...

1.8 KiB

id title challengeType videoUrl forumTopicId dashedName
56592a60ddddeae28f7aa8e1 Access Multi-Dimensional Arrays With Indexes 1 https://scrimba.com/c/ckND4Cq 16159 access-multi-dimensional-arrays-with-indexes

--description--

One way to think of a multi-dimensional array, is as an array of arrays. When you use brackets to access your array, the first set of brackets refers to the entries in the outer-most (the first level) array, and each additional pair of brackets refers to the next level of entries inside.

Example

const arr = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9],
  [[10, 11, 12], 13, 14]
];

arr[3];
arr[3][0];
arr[3][0][1];

arr[3] is [[10, 11, 12], 13, 14], arr[3][0] is [10, 11, 12], and arr[3][0][1] is 11.

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

--instructions--

Using bracket notation select an element from myArray such that myData is equal to 8.

--hints--

myData should be equal to 8.

assert(myData === 8);

You should be using bracket notation to read the correct value from myArray.

assert(/myData=myArray\[2\]\[1\]/.test(__helpers.removeWhiteSpace(code)));

--seed--

--after-user-code--

if(typeof myArray !== "undefined"){(function(){return "myData: " + myData + " myArray: " + JSON.stringify(myArray);})();}

--seed-contents--

const myArray = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9],
  [[10, 11, 12], 13, 14],
];

const myData = myArray[0][0];

--solutions--

const myArray = [[1, 2, 3], [4, 5, 6], [7, 8, 9], [[10, 11, 12], 13, 14]];
const myData = myArray[2][1];