JS 参考手册

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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


HTML DOM console.time() 方法

❮ Console 对象

实例

执行一个 for 循环 10 万次需要多长时间:

console.time();
for (i = 0; i < 100000; i++) {
  // some code
}
console.timeEnd();
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定义和用法

console.time() 方法在控制台视图中启动计时器。

此方法允许您为代码中的某些操作计时,以进行测试。

请使用 console.timeEnd() 方法 结束定时器并在 console.view 中显示结果。

请使用 label 参数来命名计时器,然后您就可以在同一页面上设置多个计时器。

提示: 测试控制台方法时,请确保控制台视图可见(按 F12 查看控制台)。


浏览器支持

表中的数字表示支持该方法的第一个浏览器版本。

方法
console.time() Yes 11 10 4 Yes

语法

console.time(label)

参数值

参数 类型 描述
label 字符串 可选。使用 label 参数为计时器命名。

更多实例

实例

使用 label 参数:

console.time("test1");
for (i = 0; i < 100000; i++) {
  // some code
}
console.timeEnd("test1");
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实例

哪个最快,for 循环还是 while 循环?

var i;
console.time("test for loop");
for (i = 0; i < 1000000; i++) {
  // some code
}
console.timeEnd("test for loop");

i = 0;
console.time("test while loop");
while (i < 1000000) {
  i++
}
console.timeEnd("test while loop");
亲自试一试 »

❮ Console 对象