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.

Property attributes of Symbol.match
Writable no
Enumerable no
Configurable no


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.


Disabling the isRegExp check

The following code will throw a TypeError:


// 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


Browser compatibilityUpdate compatibility data on GitHub

Chrome Edge Firefox Internet Explorer Opera Safari
Basic support 50 Yes 40 No Yes Yes
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support Yes Yes Yes 40 Yes Yes Yes
Basic support 6.0.0

See also

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