freeCodeCamp/access-multi-dimensional-arrays-with-indexes.english.md at 35c284e9a71d45ee76fda93925f76484237d1ae2

Randell Dawson e9212c61d2 fix(curriculum): Remove unnecessary assert message argument from English challenges JavaScript Algorithms and Data Structures - 01 (#36401 )

* fix: rm assert msg basic-javascript

* fix: removed more assert msg args

* fix: fixed verbiage

Co-Authored-By: Parth Parth <34807532+thecodingaviator@users.noreply.github.com>

2019-07-13 08:07:53 +01:00

2.1 KiB

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id, title, challengeType, videoUrl

id	title	challengeType	videoUrl
56592a60ddddeae28f7aa8e1	Access Multi-Dimensional Arrays With Indexes	1	https://scrimba.com/c/ckND4Cq

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

var arr = [
  [1,2,3],
  [4,5,6],
  [7,8,9],
  [[10,11,12], 13, 14]
];
arr[3]; // equals [[10,11,12], 13, 14]
arr[3][0]; // equals [10,11,12]
arr[3][0][1]; // equals 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.

Tests

tests:
  - text: <code>myData</code> should be equal to <code>8</code>.
    testString: assert(myData === 8);
  - text: You should be using bracket notation to read the correct value from <code>myArray</code>.
    testString: assert(/myData=myArray\[2\]\[1\]/.test(code.replace(/\s/g, '')));

Challenge Seed

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

// Only change code below this line.
var myData = myArray[0][0];

After Test

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

Solution

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

2.1 KiB Raw Blame History