导航
×
   ❮   
HTML CSS JavaScript PHP Go Sass W3C Colors ECMS

JS 参考手册

JS 参考手册(字母排序)

JavaScript

JS Arrays JS Boolean JS Classes JS Dates JS Error JS Global JS Iterators JS JSON JS Maps JS Math JS Numbers JS Objects JS Operators JS Assignment JS Arithmetic JS Comparison JS Logical Operators JS Bitwise Operators JS Misc Operators JS Precedence JS Promises JS RegExp Patterns JS RegExp Reference JS Sets JS Statements JS Strings JS Typed Arrays JS Typed Reference

Window

Window Object Window Console Window History Window Location Window Navigator Window Screen

HTML DOM

HTML Documents HTML Elements HTML Attributes HTML Collection HTML NodeList HTML DOMTokenList HTML Styles
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 Events

HTML Events HTML Event Objects HTML Event Properties HTML Event Methods

Web APIs

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

HTML 对象


JavaScript new Boolean() 方法


示例

创建一个布尔对象

let bool = new Boolean();
亲自试一试 »

描述

new Boolean() 方法返回一个新的布尔对象。

另请参阅:

Boolean() 方法


语法

new Boolean(value)

参数

参数 描述
value 可选
默认值为false

返回值

类型 描述
对象 一个新的布尔对象,其值为 truefalse

警告

请勿创建布尔对象。

new关键字会使代码复杂化并降低执行速度。

布尔对象可能会产生意外结果:

布尔值和布尔对象不能安全地进行比较:

let x = Boolean(false);
let y = new Boolean(false);

(x == Y) returns true
(x === Y) returns false
亲自试一试 »

比较两个 JavaScript 对象 总是 返回 false



浏览器支持

new Boolean() 是 ECMAScript 1(JavaScript 1997)的特性。

所有浏览器均支持:

Chrome Edge Firefox Safari Opera

Copyright ©2020-2026 freew3c.com All Rights Reserved 提供的内容仅用于学习和测试,不保证内容的正确性。