在此页

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

slice() method extracts a section of a string and returns it as a new string, without modifying the original string.

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.slice(beginIndex[, endIndex])
					

参数

beginIndex

The zero-based index at which to begin extraction. If negative, it is treated as str .length + beginIndex . (For example, if beginIndex is -3 it is treated as str .length - 3 .)

若 beginIndex is greater than or equal to str .length , slice() returns an empty string.

endIndex 可选

The zero-based index before which to end extraction. The character at this index will not be included.

若 endIndex 被省略， slice() extracts to the end of the string. If negative, it is treated as str .length + endIndex . (For example, if endIndex is -3 it is treated as str .length - 3 .)

返回值

A new string containing the extracted section of the string.

描述

slice() extracts the text from one string and returns a new string. Changes to the text in one string do not affect the other string.

slice() extracts up to but not including endIndex . str .slice(1, 4) extracts the second character through the fourth character (characters indexed 1 , 2 ，和 3 ).

As an example, str .slice(2, -1) extracts the third character through the second to last character in the string.

范例

使用 slice() to create a new string

以下范例使用 slice() to create a new string.

let str1 = 'The morning is upon us.', // the length of str1 is 23.
    str2 = str1.slice(1, 8),
    str3 = str1.slice(4, -2),
    str4 = str1.slice(12),
    str5 = str1.slice(30);
console.log(str2)  // OUTPUT: he morn
console.log(str3)  // OUTPUT: morning is upon u
console.log(str4)  // OUTPUT: is upon us.
console.log(str5)  // OUTPUT: ""
					

使用 slice() with negative indexes

以下范例使用 slice() with negative indexes.

let str = 'The morning is upon us.'
str.slice(-3)      // returns 'us.'
str.slice(-3, -1)  // returns 'us'
str.slice(0, -1)   // returns 'The morning is upon us'
					

This example counts backwards from the end of the string by 11 to find the start index and forwards from the start of the string by 16 to find the end index.

console.log(str.slice(-11, 16)) // => "is u"
					

Here it counts forwards from the start by 11 to find the start index and backwards from the end by 7 to find the end index.

console.log(str.slice(11, -7)) // => " is u"
					

These arguments count backwards from the end by 5 to find the start index and backwards from the end by 1 to find the end index.

console.log(str.slice(-5, -1)) // => "n us"
					

规范

规范
ECMAScript (ECMA-262) The definition of 'String.prototype.slice' 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
slice	Chrome 1	Edge 12	Firefox 1	IE 4	Opera 4	Safari 1	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 10.1	Safari iOS 1	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.substr()
• String.prototype.substring()
• Array.prototype.slice()

元数据

• 最后修改： 2020 年 3 月 26 日

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
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   2. Function.prototype.bind()
   3. Function.prototype.call()
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   5. Function.prototype.toString()
9. Object
10. 特性
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    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
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    9. Object.prototype.toSource()
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