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JS 参考

按类别分类的 JS 按字母顺序排列的 JS

JavaScript

JS 数组 JS 布尔值 JS 类 JS 日期 JS 错误 JS 全局 JS JSON JS 地图 JS 数学 JS 数字 JS 对象 JS 运算符 JS 优先级 JS Promise JS 正则表达式 JS 集合 JS 语句 JS 字符串 JS TypedArray

窗口

窗口对象 窗口控制台 窗口历史记录 窗口位置 窗口导航器 窗口屏幕

HTML DOM

HTML 文档 HTML 元素 HTML 属性 HTML 集合 HTML 节点列表 HTML DOMTokenList HTML 样式
alignContent alignItems alignSelf animation animationDelay animationDirection animationDuration animationFillMode animationIterationCount animationName animationTimingFunction animationPlayState background backgroundAttachment backgroundClip backgroundColor backgroundImage backgroundOrigin backgroundPosition backgroundRepeat 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 cssFloat cursor direction display emptyCells filter flex flexBasis flexDirection flexFlow flexGrow flexShrink flexWrap 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

HTML 事件

HTML 事件 HTML 事件对象 HTML 事件属性 HTML 事件方法

Web APIs

API Canvas API Console API Fetch API 全屏 API Geolocation API History API MediaQueryList API Storage API Validation API Web

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>

其他参考资料

CSSStyleDeclaration JS 转换


JavaScript 类

示例

创建一个 Car 类,然后基于 Car 类创建一个对象 (myCar)

// 创建一个 Car 类
class Car {
constructor(brand) {
    this.carname = brand;
  }
}

// 创建一个 Car 对象
myCar = new Car("Ford");

亲自试一试 »


描述

一个 class 是一种对象模板。

The class 语句初始化一个 JavaScript 类。

属性和方法在 constructor() 方法中分配。

The constructor() 方法在每次初始化类对象时被调用。

另请参阅

JavaScript 类.

注意

类中的语法必须以“严格模式”编写。

与函数不同,类声明不会被提升(您必须在使用类之前声明类)。


语法

class className {
  // 类体
}

相关页面

JavaScript 教程:JavaScript 类

JavaScript 教程:JavaScript ES6 (EcmaScript 2015)

JavaScript 教程:JavaScript this

JavaScript 教程:JavaScript 严格模式


浏览器支持

class 是 ECMAScript6 (ES6) 的一个特性。

ES6 (JavaScript 2015) 自 2017 年 6 月起在所有现代浏览器中得到支持

Chrome 51 Edge 15 Firefox 54 Safari 10 Opera 38
2016 年 5 月 2017 年 4 月 2017 年 6 月 2016 年 9 月 2016 年 6 月

class 不支持 Internet Explorer。


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