RegExp.prototype[@@matchAll]()

The [@@matchAll] method returns all matches of the regular expression against a 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.

Syntax

regexp[Symbol.matchAll](str)

Parameters

str

A String that is a target of the match.

Return value

An iterator.

Description

This method is called internally in String.prototype.matchAll(). For example, the following two examples return same result.

'abc'.matchAll(/a/);

/a/[Symbol.matchAll]('abc');

This method exists for customizing match behavior within RegExp subclasses.

Examples

Direct call

This method can be used in almost the same way as String.prototype.matchAll(), except the different this and the different arguments order.

var re = /[0-9]+/g;
var str = '2016-01-02';
var result = re[Symbol.matchAll](str);

console.log(Array.from(result, x => x[0]));  
// ["2016", "01", "02"]

Using @@matchAll in subclasses

Subclasses of RegExp can override the [@@matchAll]() method to modify the default behavior. For example, to return an Array instead of an iterator:

class MyRegExp extends RegExp {
  [Symbol.matchAll](str) {
    var result = RegExp.prototype[Symbol.matchAll].call(this, str);
    if (!result) { 
      return null;
    } else {
      return Array.from(result);
    }
  }
}

var re = new MyRegExp('([0-9]+)-([0-9]+)-([0-9]+)', 'g');
var str = '2016-01-02|2019-03-07';
var result = str.matchAll(re);
console.log(result[0]); // [ "2016-01-02", "2016", "01", "02" ]
console.log(result[1]); // [ "2019-03-07", "2019", "03", "07" ]

Specifications

Browser compatibility

See also

• String.prototype.matchAll()
• Symbol.matchAll