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Regular expression

Regular expressions (or regex) are rules that govern which sequences of characters come up in a search.

Regular expressions are implemented in various languages, but the best-known implementation is the Perl Implementation, which has given rise to its own ecosystem of implementations called PCRE (Perl Compatible Regular Expression). On the Web, JavaScript provides another regex implementation through the RegExp object.

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 Contributors to this page: hbloomer, Andrew_Pfeiffer, Jeremie, klez, teainthegarden
 Last updated by: hbloomer,