RegExp.prototype[@@search]()
The [@@search]()
method executes a search for a match between a this
regular expression and a string.
Syntax
JavaScript
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<var>regexp</var>[Symbol.search](str)
Parameters
str
- A
String
that is a target of the search.
Return value
- integer
- If successful,
[@@search]()
returns the index of the first match of the regular expression inside the string. Otherwise, it returns -1.
Description
This method is called internally in String.prototype.search()
. For example, the following two examples return the same result.
JavaScript
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'abc'.search(/a/); /a/[Symbol.search]('abc');
This method exists for customizing the search behavior in RegExp
subclasses.
Examples
Direct call
This method can be used in almost the same way as String.prototype.search()
, except the different this
and the different arguments order.
JavaScript
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var re = /-/g; var str = '2016-01-02'; var result = re[Symbol.search](str); console.log(result); // 4
Using @@search
in subclasses
Subclass of RegExp
can override [@@search]()
method to modify the behavior.
JavaScript
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class MyRegExp extends RegExp { constructor(str) { super(str) this.pattern = str; } [Symbol.search](str) { return str.indexOf(this.pattern); } } var re = new MyRegExp('a+b'); var str = 'ab a+b'; var result = str.search(re); // String.prototype.search calls re[@@search]. console.log(result); // 3
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'RegExp.prototype[@@search]' in that specification. |
Standard | Initial definition. |
ECMAScript 2017 Draft (ECMA-262) The definition of 'RegExp.prototype[@@search]' in that specification. |
Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | ? | 49 (49) | ? | ? | ? |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | ? | ? | 49.0 (49) | ? | ? | ? |
See also
String.prototype.search()
RegExp.prototype[@@match]()
RegExp.prototype[@@replace]()
RegExp.prototype[@@split]()
RegExp.prototype.exec()
RegExp.prototype.test()
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/regexp/@@search