String.prototype.trim()

trim() 方法会从一个字符串的两端删除空白字符。在这个上下文中的空白字符是所有的空白字符 (space, tab, no-break space 等) 以及所有行终止符字符(如 LF,CR等)。

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语法

str.trim()

返回值

一个代表调用字符串两端去掉空白的新字符串。

描述

trim()方法返回一个两头都去掉空白的字符串,并不影响原字符串本身。

例子

使用 trim()

下面的例子中将显示小写的字符串 'foo':

var orig = '   foo  ';
console.log(orig.trim()); // 'foo'

// 另一个.trim()例子,只从一边删除

var orig = 'foo    ';
console.log(orig.trim()); // 'foo'

兼容旧环境

如果 trim() 不存在,可以在所有代码前执行下面代码

if (!String.prototype.trim) {
  String.prototype.trim = function () {
    return this.replace(/^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g, '');
  };
}

规范

Specification Status Comment
ECMAScript 5.1 (ECMA-262)
String.prototype.trim
Standard Initial definition. Implemented in JavaScript 1.8.1.
ECMAScript 2015 (6th Edition, ECMA-262)
String.prototype.trim
Standard
ECMAScript Latest Draft (ECMA-262)
String.prototype.trim
Draft

浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!
Feature Firefox (Gecko) Chrome Internet Explorer Opera Safari
Basic support 3.5 (1.9.1) (Yes) 9 10.5 5
Feature Firefox Mobile (Gecko) Android IE Mobile Opera Mobile Safari Mobile
Basic support ? ? ? ? ?

相关链接