Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

#include <StringConstants.au3> ; to declare the Constants of StringRegExp #include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate Local $sRegex = "(?m)^(?P<indentation>(?P<sp_or_tab>[ \t])*+)(?P<stmt>(?P<non_str_lit>(?:(?!\#)[^\"'\r\n])*?)(?:(?P<str_lit>(?P<begin_quote>(?P<single_quote>')|\")(?:(?(single_quote)\"|')|\\[\"']|\\[^\r\n ]|[^\"'\\\r\n])*?(?P=begin_quote))(?&non_str_lit))*?)(?P<whitespace>(?&sp_or_tab)*+)(?P<comment>(?:\#)[^\r\n]*+)?(?P<line_ending>\r|\n|\r\n)?$" Local $sString = "print("Hello, world!") # this is a comment." & @CRLF & _ "print("The quick \\brown\\\ndog\rfox\tjumps\t over #the# /lazy/ \"dog\"###") # and here's where the real comment starts" & @CRLF & _ " print("you can use Alt+0009 to enter a tab character!")" & @CRLF & _ "# The above line had no comments, so the <comment> group didn't participate in the match." & @CRLF & _ " print("indented code") # with comment" & @CRLF & _ " print("never indent code like this, but it still matches anyway")# comment lacking preceding whitespace >:)" & @CRLF & _ " print("space indented code")" & @CRLF & _ "print("Missing end quote" & @CRLF & _ "print("unescaped \")" & @CRLF & _ "print("implicitly" " joined## " "string " "lit#erals") # a line can contain multiple string literals" & @CRLF & _ "print("the quick " # line 1" & @CRLF & _ " "brown fox " # line 2" & @CRLF & _ " "jumps over " # line 3" & @CRLF & _ " "the lazy dog") # line 4" & @CRLF & _ "" & @CRLF & _ " print("The quick brown", animal, "jumps over the", adjective, animal2, sep=" ") "" & @CRLF & _ "print('Robert'); DROP TABLE `Students`; -- ')" Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH) Local $aFullArray[0] For $i = 0 To UBound($aArray) -1 _ArrayConcatenate($aFullArray, $aArray[$i]) Next $aArray = $aFullArray ; Present the entire match result _ArrayDisplay($aArray, "Result")

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm