# “Regex” vs. “regexp”

Different programming languages use different abbreviations for the term "regular expression".
"Regex" is [dominant overall](https://stackoverflow.com/a/3058254) but not as overwhelmingly dominant as you may think.

Each item in the following list is a link to documentation.
We ignore differences in captalization, which varies.

## Contents

## "Regex"

- [BlitzMax](https://www.blitzmax.org/docs/en/api/text/text.regex/)
- [C#](https://learn.microsoft.com/en-us/dotnet/api/system.text.regularexpressions.regex?view=net-10.0)
- [Crystal](https://crystal-lang.org/api/1.18.0/Regex.html)
- [Dephi](http://docwiki.embarcadero.com/Libraries/Sydney/en/System.RegularExpressions)
- [Elixir](https://hexdocs.pm/elixir/1.19.0/Regex.html)
- [Haskell](https://wiki.haskell.org/Regular_expressions)
- [Java](https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/util/regex/Pattern.html)
- [Julia](https://docs.julialang.org/en/v1/manual/strings/#man-regex-literals)
- [Mathematica, Wolfram Language](https://reference.wolfram.com/language/ref/RegularExpression.html)
- [MIRC scripting language](https://www.mirc.com/help/html/index.html?regular_expressions.html)
- [Nim](https://nim-lang.org/docs/re.html)
- [Objective-C, Swift](https://developer.apple.com/documentation/foundation/nsregularexpression)
- [Perl](https://perldoc.perl.org/perlre) (but also ["regexp"](https://perldoc.perl.org/perlop#Regexp-Quote-Like-Operators)---there is more than one way to do it)
- [PHP](https://www.php.net/manual/en/book.pcre.php)
- [POSIX C](https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/regex.h.html)
- [Python](https://docs.python.org/3/library/re.html)

## "Regexp"

- [Dart](https://api.dart.dev/dart-core/RegExp-class.html)
- [Erlang](https://erlang.org/doc/man/re.html)
- [Factor](https://docs.factorcode.org/content/word-regexp%2Cregexp.html)
- [Go](https://golang.org/pkg/regexp/)
- [JavaScript](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp)
- [MATLAB](https://www.mathworks.com/help/matlab/ref/regexp.html)
- [OCaml](https://v2.ocaml.org/api/Str.html)
- [Racket](https://docs.racket-lang.org/reference/regexp.html)
- [Ruby](https://docs.ruby-lang.org/en/4.0/Regexp.html)
- [Scheme (SRFI 115)](https://srfi.schemers.org/srfi-115/srfi-115.html)
- [Tcl](https://www.tcl-lang.org/man/tcl9.0/TclCmd/regexp.html)

## "Regexpr"

- [Free Pascal](https://wiki.freepascal.org/Regexpr)

## Page metadata

URL: <https://dbohdan.com/regex-vs-regexp.md>

Published 2021-06-24, updated 2025-12-29.

Tags:

- natural language
- programming