freeCodeCamp/use-destructuring-assignment-to-assign-variables-from-arrays.english.md at aa050465e9c42cc50be91281c037cfac59500161

gaspersic/freeCodeCamp

Fork 0

Files

.github

api-server

client

config

curriculum

challenges

_meta

arabic

chinese

english

01-responsive-web-design

02-javascript-algorithms-and-data-structures

basic-algorithm-scripting

basic-data-structures

basic-javascript

debugging

es6

compare-scopes-of-the-var-and-let-keywords.english.md

create-an-export-fallback-with-export-default.english.md

create-strings-using-template-literals.english.md

declare-a-read-only-variable-with-the-const-keyword.english.md

explore-differences-between-the-var-and-let-keywords.english.md

import-a-default-export.english.md

mutate-an-array-declared-with-const.english.md

prevent-object-mutation.english.md

set-default-parameters-for-your-functions.english.md

understand-the-differences-between-import-and-require.english.md

use--to-import-everything-from-a-file.english.md

use-arrow-functions-to-write-concise-anonymous-functions.english.md

use-class-syntax-to-define-a-constructor-function.english.md

use-destructuring-assignment-to-assign-variables-from-arrays.english.md

use-destructuring-assignment-to-assign-variables-from-nested-objects.english.md

use-destructuring-assignment-to-assign-variables-from-objects.english.md

use-destructuring-assignment-to-pass-an-object-as-a-functions-parameters.english.md

use-destructuring-assignment-with-the-rest-operator-to-reassign-array-elements.english.md

use-export-to-reuse-a-code-block.english.md

use-getters-and-setters-to-control-access-to-an-object.english.md

use-the-rest-operator-with-function-parameters.english.md

use-the-spread-operator-to-evaluate-arrays-in-place.english.md

write-arrow-functions-with-parameters.english.md

write-concise-declarative-functions-with-es6.english.md

write-concise-object-literal-declarations-using-simple-fields.english.md

write-higher-order-arrow-functions.english.md

functional-programming

intermediate-algorithm-scripting

javascript-algorithms-and-data-structures-projects

object-oriented-programming

regular-expressions

03-front-end-libraries

04-data-visualization

05-apis-and-microservices

06-information-security-and-quality-assurance

08-coding-interview-prep

09-certificates

portuguese

russian

spanish

formattingConversion

math-challenges

requiresTests

schema

test

.babelrc

.editorconfig

.eslintignore

.eslintrc

.npmignore

.prettierrc

.travis.yml

CHANGELOG.md

LICENSE.md

commitizen.config.js

commitlint.config.js

create-challenge-bundle.js

getChallenges.js

gulpfile.js

index.js

lib.js

md-translation.js

package-entry.js

package-lock.json

package.json

repack.js

unpack.js

unpacked.css

unpacked.js

unpackedChallenge.js

utils.js

docs

guide

mock-guide

news

tools

.editorconfig

.eslintignore

.eslintrc

.gitattributes

.gitignore

.node-inspectorrc

.prettierrc

.snyk

.travis.yml

.vcmrc

CODE_OF_CONDUCT.md

CONTRIBUTING.md

LICENSE.md

README(french).md

README.md

docker-compose-shared.yml

docker-compose.yml

lerna.json

netlify.toml

package-lock.json

package.json

sample.env

Valeriy 79d9012432 fix(curriculum): quotes in tests (#18828 )

* fix(curriculum): tests quotes

* fix(curriculum): fill seed-teardown

* fix(curriculum): fix tests and remove unneeded seed-teardown

2018-10-20 23:32:47 +05:30

2.1 KiB

Raw Blame History

id, title, challengeType

id	title	challengeType
587d7b89367417b2b2512b4b	Use Destructuring Assignment to Assign Variables from Arrays	1

Description

ES6 makes destructuring arrays as easy as destructuring objects. One key difference between the spread operator and array destructuring is that the spread operator unpacks all contents of an array into a comma-separated list. Consequently, you cannot pick or choose which elements you want to assign to variables. Destructuring an array lets us do exactly that:

const [a, b] = [1, 2, 3, 4, 5, 6];
console.log(a, b); // 1, 2

The variable a is assigned the first value of the array, and b is assigned the second value of the array. We can also access the value at any index in an array with destructuring by using commas to reach the desired index:

const [a, b,,, c] = [1, 2, 3, 4, 5, 6];
console.log(a, b, c); // 1, 2, 5

Instructions

Use destructuring assignment to swap the values of a and b so that a receives the value stored in b, and b receives the value stored in a.

Tests

tests:
  - text: Value of <code>a</code> should be 6, after swapping.
    testString: assert(a === 6, 'Value of <code>a</code> should be 6, after swapping.');
  - text: Value of <code>b</code> should be 8, after swapping.
    testString: assert(b === 8, 'Value of <code>b</code> should be 8, after swapping.');
  - text: Use array destructuring to swap a and b.
    testString: // assert(/\[\s*(\w)\s*,\s*(\w)\s*\]\s*=\s*\[\s*\2\s*,\s*\1\s*\]/g.test(code), 'Use array destructuring to swap a and b.');

Challenge Seed

let a = 8, b = 6;
(() => {
  "use strict";
  // change code below this line

  // change code above this line
})();
console.log(a); // should be 6
console.log(b); // should be 8

Solution

// solution required

2.1 KiB Raw Blame History