mirror of
https://github.com/freeCodeCamp/freeCodeCamp.git
synced 2026-01-03 06:03:23 -05:00
95561b0cb4
* Fixed several typos and grammar errors * Revert to an because the context is english US * Fixed some weird wording * Switch a to an Co-authored-by: Ilenia <nethleen@gmail.com> Co-authored-by: Ilenia <nethleen@gmail.com>
79 lines
1.9 KiB
Markdown
79 lines
1.9 KiB
Markdown
---
|
|
id: 56592a60ddddeae28f7aa8e1
|
|
title: Access Multi-Dimensional Arrays With Indexes
|
|
challengeType: 1
|
|
videoUrl: 'https://scrimba.com/c/ckND4Cq'
|
|
forumTopicId: 16159
|
|
dashedName: access-multi-dimensional-arrays-with-indexes
|
|
---
|
|
|
|
# --description--
|
|
|
|
One way to think of a <dfn>multi-dimensional</dfn> 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 outermost (the first level) array, and each additional pair of brackets refers to the next level of entries inside.
|
|
|
|
**Example**
|
|
|
|
```js
|
|
const arr = [
|
|
[1, 2, 3],
|
|
[4, 5, 6],
|
|
[7, 8, 9],
|
|
[[10, 11, 12], 13, 14]
|
|
];
|
|
|
|
const subarray = arr[3];
|
|
const nestedSubarray = arr[3][0];
|
|
const element = arr[3][0][1];
|
|
```
|
|
|
|
In this example, `subarray` has the value `[[10, 11, 12], 13, 14]`,
|
|
`nestedSubarray` has the value `[10, 11, 12]`, and `element` has the value `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`.
|
|
|
|
```js
|
|
assert(myData === 8);
|
|
```
|
|
|
|
You should be using bracket notation to read the correct value from `myArray`.
|
|
|
|
```js
|
|
assert(/myData=myArray\[2\]\[1\]/.test(__helpers.removeWhiteSpace(code)));
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --after-user-code--
|
|
|
|
```js
|
|
if(typeof myArray !== "undefined"){(function(){return "myData: " + myData + " myArray: " + JSON.stringify(myArray);})();}
|
|
```
|
|
|
|
## --seed-contents--
|
|
|
|
```js
|
|
const myArray = [
|
|
[1, 2, 3],
|
|
[4, 5, 6],
|
|
[7, 8, 9],
|
|
[[10, 11, 12], 13, 14],
|
|
];
|
|
|
|
const myData = myArray[0][0];
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```js
|
|
const myArray = [[1, 2, 3], [4, 5, 6], [7, 8, 9], [[10, 11, 12], 13, 14]];
|
|
const myData = myArray[2][1];
|
|
```
|