在此页

• 句法
• 描述
• Polyfill
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

trim() method removes whitespace from both ends of a string. Whitespace in this context is all the whitespace characters (space, tab, no-break space, etc.) and all the line terminator characters (LF, CR, etc.).

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

句法

str.trim()
					

返回值

A new string representing the str stripped of whitespace from both ends.

描述

trim() method returns the string stripped of whitespace from both ends. trim() does not affect the value of the str 本身。

Polyfill

Running the following code before any other code will create trim() if it's not natively available.

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

范例

使用 trim()

The following example displays the lowercase string 'foo' :

var orig = '   foo  ';
console.log(orig.trim()); // 'foo'
// Another example of .trim() removing whitespace from just one side.
var orig = 'foo    ';
console.log(orig.trim()); // 'foo'
					

规范

规范
ECMAScript (ECMA-262) The definition of 'String.prototype.trim' in that specification.

浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

更新 GitHub 上的兼容性数据

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
trim	Chrome 4	Edge 12	Firefox 3.5	IE 9	Opera 10.5	Safari 5	WebView Android ≤37	Chrome Android 18	Firefox Android 4	Opera Android 11	Safari iOS 5	Samsung Internet Android 1.0	nodejs 0.1.100

图例

完整支持

完整支持

另请参阅

• String.prototype.trimStart()
• String.prototype.trimEnd()

元数据

• 最后修改： May 20, 2020

相关话题

1. 标准内置对象
2. String
3. 特性
   1. String 长度
4. 方法
   1. String.fromCharCode()
   2. String.fromCodePoint()
   3. String.prototype.anchor()
   4. String.prototype.big()
   5. String.prototype.blink()
   6. String.prototype.bold()
   7. String.prototype.charAt()
   8. String.prototype.charCodeAt()
   9. String.prototype.codePointAt()
   10. String.prototype.concat()
   11. String.prototype.endsWith()
   12. String.prototype.fixed()
   13. String.prototype.fontcolor()
   14. String.prototype.fontsize()
   15. String.prototype.includes()
   16. String.prototype.indexOf()
   17. String.prototype.italics()
   18. String.prototype.lastIndexOf()
   19. String.prototype.link()
   20. String.prototype.localeCompare()
   21. String.prototype.match()
   22. String.prototype.matchAll()
   23. String.prototype.normalize()
   24. String.prototype.padEnd()
   25. String.prototype.padStart()
   26. String.prototype.repeat()
   27. String.prototype.replace()
   28. String.prototype.replaceAll()
   29. String.prototype.search()
   30. String.prototype.slice()
   31. String.prototype.small()
   32. String.prototype.split()
   33. String.prototype.startsWith()
   34. String.prototype.strike()
   35. String.prototype.sub()
   36. String.prototype.substr()
   37. String.prototype.substring()
   38. String.prototype.sup()
   39. String.prototype.toLocaleLowerCase()
   40. String.prototype.toLocaleUpperCase()
   41. String.prototype.toLowerCase()
   42. String.prototype.toSource()
   43. String.prototype.toString()
   44. String.prototype.toUpperCase()
   45. String.prototype.trim()
   46. String.prototype.trimEnd()
   47. String.prototype.trimStart()
   48. String.prototype.valueOf()
   49. String.prototype[@@iterator]()
   50. String.raw()
5. 继承：
6. Function
7. 特性
   1. Function.arguments
   2. Function.caller
   3. Function.displayName
   4. Function.length
   5. Function.name
8. 方法
   1. Function.prototype.apply()
   2. Function.prototype.bind()
   3. Function.prototype.call()
   4. Function.prototype.toSource()
   5. Function.prototype.toString()
9. Object
10. 特性
    1. Object.prototype.__proto__
    2. Object.prototype.constructor
11. 方法
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.valueOf()
    12. Object.setPrototypeOf()