[フレーム]

JS Tutorial

JS HOME JS Introduction JS Where To JS Output JS Syntax JS Statements JS Comments JS Variables JS Let JS Const JS Operators JS Arithmetic JS Assignment JS Functions JS Objects JS Events JS Strings JS String Templates JS Numbers JS Arrays JS Dates JS Math JS Booleans JS Comparisons JS Logical JS If Else JS Switch JS Loops JS Break JS Continue JS Errors JS Scope JS Code Blocks JS UTF-8 Characters JS News 2025-2015

JS Statements

JS Statements JS Keywords Reference JS Keywords Reserved

JS Operators

JS Assignment JS Arithmetic JS Comparison JS Logical Operators JS Bitwise Operators JS Operator Reference JS Operator Precedence

JS Data Types

JS Data Types JS typeof JS toString() JS Type Conversion

JS Strings

JS String Methods JS String Search JS String Reference

JS Numbers

JS Number Methods JS Number Properties JS Number Reference JS Math Reference JS Random JS BigInt JS Bitwise

JS Dates

JS Date Formats JS Date Get JS Date Set JS Date Reference

JS Arrays

JS Array Methods JS Array Search JS Array Sort JS Array Iterations JS Array Reference JS Array Const

JS Functions

Function Definitions Function Arrows Function Parameters Function Invocation Function this Function Call Function Apply Function Bind Function Closures

JS Objects

Object Definitions Object Properties Object Methods Object Display Object Constructors Object this Object Destructuring Object Prototypes Object Iterations Object Management Object Get / Set Object Protection Object Reference

JS Classes

JS Classes JS Class Inheritance JS Class Static

JS Sets & Maps

JS Sets JS Set Methods JS Set Logic JS Set WeakSet JS Set Reference JS Maps JS Map Methods JS Map WeakMap JS Map Reference

JS Iterations

JS Loops JS Loop for JS Loop while JS Loop for...in JS Loop for...of JS Iterables JS Iterators JS Generators

JS RegExp

JS RegExp JS RegExp Flags JS RegExp Classes JS RegExp Metachars JS RegExp Assertions JS RegExp Quantifiers JS RegExp Patterns JS RegExp Objects JS RegExp Methods

JS Typed Arrays

JS Typed Arrays JS Typed Methods JS Typed Reference

JS Async

JS Callbacks JS Asynchronous JS Promises JS Async/Await

JS Versions

JS Versions JS 2009 (ES5) JS 2015 (ES6) JS 2016 JS 2017 JS 2018 JS 2019 JS 2020 JS 2021 JS 2022 JS 2023 JS 2024 JS 2025 JS IE / Edge JS History

JS Programming

JS Strict Mode JS Scopes JS Hoisting JS Debugging JS Modules JS Style Guide JS Best Practices JS Mistakes JS Performance

JS HTML DOM

DOM Intro DOM Methods DOM Document DOM Elements DOM HTML DOM Forms DOM CSS DOM Animations DOM Events DOM Event Listener DOM Navigation DOM Nodes DOM Collections DOM Node Lists

JS Browser BOM

JS Window JS Screen JS Location JS History JS Navigator JS Popup Alert JS Timing JS Cookies

JS Web APIs

Web API Intro Web Validation API Web History API Web Storage API Web Worker API Web Fetch API Web Geolocation API

JS AJAX

AJAX Intro AJAX XMLHttp AJAX Request AJAX Response AJAX XML File AJAX PHP AJAX ASP AJAX Database AJAX Applications AJAX Examples

JS JSON

JSON Intro JSON Syntax JSON vs XML JSON Data Types JSON Parse JSON Stringify JSON Objects JSON Arrays JSON Server JSON PHP JSON HTML JSON JSONP

JS vs jQuery

jQuery Selectors jQuery HTML jQuery CSS jQuery DOM

JS Graphics

JS Graphics JS Canvas JS Plotly JS Chart.js JS Google Chart JS D3.js

JS Examples

JS Examples JS HTML DOM JS HTML Input JS HTML Objects JS HTML Events JS Browser JS Editor JS Exercises JS Quiz JS Website JS Syllabus JS Study Plan JS Interview Prep JS Bootcamp JS Certificate

JS References

JavaScript Objects HTML DOM Objects


Assignment Operators

JavaScript Assignments

Assignment operators assign values to variables.

Given that x = 10 and y = 5, the table below explains the assignment operators:

Oper Example Same As Result
= x = y x = y x = 5 Try it »
+= x += y x = x + y x = 15 Try it »
-= x -= y x = x - y x = 5 Try it »
*= x *= y x = x * y x = 50 Try it »
/= x /= y x = x / y x = 2 Try it »
%= x %= y x = x % y x = 0 Try it »
: x: 45 size.x = 45 x = 45 Try it »

Logical Assignment Operators

Oper Example Result
&&= true &&= 10 x = 10 Try it »
||= false ||= 10 x = 10 Try it »
??= null ??= 10 x = 10 Try it »

The Spread (...) Operator

The ... operator splits iterables into individual elements.

Syntax Example
const myArr = [1, 2, 3]; let xMin = Math.min(...myArr); Try it »

Learn More:

Study our JavaScript Assignment Tutorial.

Track your progress - it's free!
×

Contact Sales

If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail:
sales@w3schools.com

Report Error

If you want to report an error, or if you want to make a suggestion, send us an e-mail:
help@w3schools.com

FORUM ABOUT ACADEMY
W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning.
Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness
of all content. While using W3Schools, you agree to have read and accepted our terms of use, cookie and privacy policy.

Copyright 1999-2025 by Refsnes Data. All Rights Reserved. W3Schools is Powered by W3.CSS.

AltStyle によって変換されたページ (->オリジナル) /