MatchAll

MatchAll is a JavaScript string method that returns an iterator over all matches of a regular expression against a string. Introduced with ECMAScript 2020, it enables retrieving every occurrence, including capture groups, rather than stopping at the first match. The regular expression passed to matchAll must have the global flag (/g).

Each item yielded by the iterator is a RegExp match array. The full matched text is at index 0, and any captured groups appear at subsequent indices. If the regex defines named capture groups, the yielded object also includes a groups property with those values. This makes matchAll useful when you need detailed information from every match.

Because matchAll returns an iterator, you typically consume it with a for...of loop or by converting it to an array, for example with Array.from or the spread operator. This contrasts with String.prototype.match using a global regex, which returns only an array of strings without capture groups.

Usage notes: ensure the environment supports ECMAScript 2020 features, as older runtimes may not implement matchAll. If you need to reuse results, convert the iterator to a collection immediately, since an iterator is typically consumed once.

Example concept: for a string like "cat1 dog2" and a global regex /(\w+)(\d)/g, matchAll yields two matches with both full text and the two capture groups for each match. This approach is particularly helpful when you need structured data from all occurrences across the input.