JS 参考手册

JS 参考手册(类别排序) JS 参考手册(字母排序)

JavaScript

JS Array JS Boolean JS Classes JS Date JS Error JS Global JS JSON JS Math JS Number JS 运算符 JS RegExp JS 语句 JS String

HTML DOM

DOM Attributes DOM Document DOM Element DOM Events DOM Event 对象 DOM HTMLCollection DOM Location DOM Navigator DOM Screen DOM Style
alignContent alignItems alignSelf animation animationDelay animationDirection animationDuration animationFillMode animationIterationCount animationName animationTimingFunction animationPlayState background backgroundAttachment backgroundColor backgroundImage backgroundPosition backgroundRepeat backgroundClip backgroundOrigin backgroundSize backfaceVisibility border borderBottom borderBottomColor borderBottomLeftRadius borderBottomRightRadius borderBottomStyle borderBottomWidth borderCollapse borderColor borderImage borderImageOutset borderImageRepeat borderImageSlice borderImageSource borderImageWidth borderLeft borderLeftColor borderLeftStyle borderLeftWidth borderRadius borderRight borderRightColor borderRightStyle borderRightWidth borderSpacing borderStyle borderTop borderTopColor borderTopLeftRadius borderTopRightRadius borderTopStyle borderTopWidth borderWidth bottom boxShadow boxSizing captionSide caretColor clear clip color columnCount columnFill columnGap columnRule columnRuleColor columnRuleStyle columnRuleWidth columns columnSpan columnWidth counterIncrement counterReset cursor direction display emptyCells filter flex flexBasis flexDirection flexFlow flexGrow flexShrink flexWrap cssFloat font fontFamily fontSize fontStyle fontVariant fontWeight fontSizeAdjust height isolation justifyContent left letterSpacing lineHeight listStyle listStyleImage listStylePosition listStyleType margin marginBottom marginLeft marginRight marginTop maxHeight maxWidth minHeight minWidth objectFit objectPosition opacity order orphans outline outlineColor outlineOffset outlineStyle outlineWidth overflow overflowX overflowY padding paddingBottom paddingLeft paddingRight paddingTop pageBreakAfter pageBreakBefore pageBreakInside perspective perspectiveOrigin position quotes resize right scrollBehavior tableLayout tabSize textAlign textAlignLast textDecoration textDecorationColor textDecorationLine textDecorationStyle textIndent textOverflow textShadow textTransform top transform transformOrigin transformStyle transition transitionProperty transitionDuration transitionTimingFunction transitionDelay unicodeBidi userSelect verticalAlign visibility width wordBreak wordSpacing wordWrap widows zIndex
DOM Window

Web APIs

API Console API Geolocation API History API Storage

HTML 对象

<a> <abbr> <address> <area> <article> <aside> <audio> <b> <base> <bdo> <blockquote> <body> <br> <button> <canvas> <caption> <cite> <code> <col> <colgroup> <datalist> <dd> <del> <details> <dfn> <dialog> <div> <dl> <dt> <em> <embed> <fieldset> <figcaption> <figure> <footer> <form> <head> <header> <h1> - <h6> <hr> <html> <i> <iframe> <img> <ins> <input> button <input> checkbox <input> color <input> date <input> datetime <input> datetime-local <input> email <input> file <input> hidden <input> image <input> month <input> number <input> password <input> radio <input> range <input> reset <input> search <input> submit <input> text <input> time <input> url <input> week <kbd> <label> <legend> <li> <link> <map> <mark> <menu> <menuitem> <meta> <meter> <nav> <object> <ol> <optgroup> <option> <output> <p> <param> <pre> <progress> <q> <s> <samp> <script> <section> <select> <small> <source> <span> <strong> <style> <sub> <summary> <sup> <table> <tbody> <td> <tfoot> <th> <thead> <tr> <textarea> <time> <title> <track> <u> <ul> <var> <video>

其他参考手册

CSSStyleDeclaration JS 类型转换


JavaScript return 语句


实例

返回 PI 的值:

function myFunction() {
  return Math.PI;
}
亲自试一试 »

页面下方有更多实例。


定义和用法

return 语句停止函数的执行并从函数返回一个值。

请阅读我们的 JavaScript 教程,学习您需要的有关函数的所有知识。请从关于 JavaScript 函数和 JavaScript 作用域的章节开始。更多详细信息,请参阅我们关于函数定义、参数、调用和闭包的教程。

阅读我们的 JavaScript 教程,了解您需要了解的有关函数的所有信息。 从 JavaScript 函数JavaScript 作用域 介绍章节开始。 有关更多详细信息,请参阅我们关于函数定义函数参数调用闭包


浏览器支持

Statement
return Yes Yes Yes Yes Yes

语法

return value;

参数值

参数 描述
value 可选。指定要返回给函数调用者的值。如果省略,则返回 undefined。


技术细节

JavaScript 版本: ECMAScript 1

更多实例

实例

使用 return 语句在 <p> 元素中显示名字 "John":

function myFunction(name) {
  return "Hello " + name;
}
document.getElementById("demo").innerHTML = myFunction("John");
亲自试一试 »

实例

计算两个数的乘积,并返回结果:

var x = myFunction(4, 3);        // Function is called, return value will end up in x

function myFunction(a, b) {
  return a * b;                // Function returns the product of a and b
}
亲自试一试 »

相关页面

JavaScript 教程: JavaScript 函数

JavaScript 教程: JavaScript 作用域

JavaScript 教程: JavaScript 函数定义

JavaScript 教程: JavaScript 函数参数

JavaScript 教程: JavaScript 函数调用

JavaScript 教程: JavaScript 函数闭包

JavaScript 参考手册: JavaScript 函数语句