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• 描述
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

sticky property reflects whether or not the search is sticky (searches in strings only from the index indicated by the lastIndex property of this regular expression). sticky is a read-only property of an individual regular expression object.

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.

特性属性在 RegExp.prototype.sticky
可写	no
可枚举	no
可配置	yes

描述

值 sticky 是 布尔 and true if the " y " flag was used; otherwise, false. The " y " flag indicates that it matches only from the index indicated by the lastIndex property of this regular expression in the target string (and does not attempt to match from any later indexes). A regular expression defined as both sticky and global ignores the global 标志。

You cannot change this property directly. It is read-only.

范例

Using a regular expression with the sticky flag

var str = '#foo#';
var regex = /foo/y;
regex.lastIndex = 1;
regex.test(str); // true
regex.lastIndex = 5;
regex.test(str); // false (lastIndex is taken into account with sticky flag)
regex.lastIndex; // 0 (reset after match failure)
					

Anchored sticky flag

For several versions, Firefox's SpiderMonkey engine had a bug with regard to the ^ assertion and the sticky flag which allowed expressions starting with the ^ assertion and using the sticky flag to match when they shouldn't. The bug was introduced some time after Firefox 3.6 (which had the sticky flag but not the bug) and fixed in 2015. Perhaps because of the bug, the ES2015 specification specifically calls out the fact that:

When the y flag is used with a pattern, ^ always matches only at the beginning of the input, or (if multiline is true ) at the beginning of a line.

Examples of correct behavior:

var regex = /^foo/y;
regex.lastIndex = 2;
regex.test('..foo');   // false - index 2 is not the beginning of the string
var regex2 = /^foo/my;
regex2.lastIndex = 2;
regex2.test('..foo');  // false - index 2 is not the beginning of the string or line
regex2.lastIndex = 2;
regex2.test('.\nfoo'); // true - index 2 is the beginning of a line
					

规范

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

浏览器兼容性

The compatibility table on 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
sticky	Chrome 49	Edge 13	Firefox 3	IE No	Opera 36	Safari 10	WebView Android 49	Chrome Android 49	Firefox Android 4	Opera Android 36	Safari iOS 10	Samsung Internet Android 5.0	nodejs Yes
Anchored sticky flag behavior per ES2015	Chrome 49	Edge 13	Firefox 44	IE No	Opera 36	Safari 10	WebView Android 49	Chrome Android 49	Firefox Android 44	Opera Android 36	Safari iOS 10	Samsung Internet Android 5.0	nodejs ?
Prototype accessor property (ES2015)	Chrome 49	Edge 13	Firefox 38	IE No	Opera 36	Safari 10	WebView Android 49	Chrome Android 49	Firefox Android 38	Opera Android 36	Safari iOS 10	Samsung Internet Android 5.0	nodejs Yes

图例

完整支持

完整支持

不支持

不支持

兼容性未知 ?

兼容性未知

另请参阅

• RegExp.lastIndex
• RegExp.prototype.global
• RegExp.prototype.ignoreCase
• RegExp.prototype.multiline
• RegExp.prototype.source

元数据

• 最后修改： Mar 20, 2020

相关话题

1. 标准内置对象
2. RegExp
3. 特性
   1. RegExp.$1-$9
   2. RegExp.input ($_)
   3. RegExp.lastMatch ($&)
   4. RegExp.lastParen ($+)
   5. RegExp.leftContext ($`)
   6. RegExp.prototype.dotAll
   7. RegExp.prototype.flags
   8. RegExp.prototype.global
   9. RegExp.prototype.ignoreCase
   10. RegExp.prototype.multiline
   11. RegExp.prototype.source
   12. RegExp.prototype.sticky
   13. RegExp.prototype.unicode
   14. RegExp.rightContext ($')
   15. RegExpInstance.lastIndex
   16. get RegExp[@@species]
4. 方法
   1. RegExp.prototype.compile()
   2. RegExp.prototype.exec()
   3. RegExp.prototype.test()
   4. RegExp.prototype.toSource()
   5. RegExp.prototype.toString()
   6. RegExp.prototype[@@matchAll]()
   7. RegExp.prototype[@@match]()
   8. RegExp.prototype[@@replace]()
   9. RegExp.prototype[@@search]()
   10. RegExp.prototype[@@split]()
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()