The Symbol.match
well-known symbol specifies the matching of a regular expression against a string. This function is called by the String.prototype.match()
method.
Symbol.match
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Description
This function is also used to identify if objects have the behavior of regular expressions. For example, the methods String.prototype.startsWith()
, String.prototype.endsWith()
and String.prototype.includes()
, check if their first argument is a regular expression and will throw a TypeError
if they are. Now, if the match
symbol is set to false
(or a Falsy value), it indicates that the object is not intended to be used as a regular expression object.
Property attributes of Symbol.match |
|
---|---|
Writable | no |
Enumerable | no |
Configurable | no |
Examples
Disabling the isRegExp
check
The following code will throw a TypeError
:
'/bar/'.startsWith(/bar/); // Throws TypeError, as /bar/ is a regular expression // and Symbol.match is not modified.
However, if you set Symbol.match
to false
, the isRegExp
check (that uses the match
property) will indicate that the object is not a regular expression object. The methods startsWith
and endsWith
won't throw a TypeError
as a consequence.
var re = /foo/; re[Symbol.match] = false; '/foo/'.startsWith(re); // true '/baz/'.endsWith(re); // false
Specifications
Specification |
---|
ECMAScript Language Specification # sec-symbol.match |
Browser compatibility
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | Deno | Node.js | |
match |
50
|
79
|
40
|
No
|
37
|
10
|
50
|
50
|
40
|
37
|
10
|
5.0
|
1.0
|
6.0.0
|
See also
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/match