Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

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

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @" +(?=[^[\]]*\])"; string input = @"0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 [-0.01357987 0.99989218 -0.00558794] [ 0.50810066 0.81535196 -0.27755161] -18017079.1047535 10307726.258588774 -23524317.110919423 22838.17515528947 36648.54674929567 -12475.426190771163 20757272.462656207 5 5 0.005 0 5 2 0.0005 3 -98.28031520537542 29.516134353642414 19998.73252382984 -0.0055879708379507065 -0.06085533474930652 359.2218946628823 818.306543386653 2.7826806154507513 8.100054108045068 -0.7584403000503389 -0.02994106840115437 -0.0628111825224635 0.058338781314879004 242.42818865783832 0.0 0.8063781178568004 -2.6036838124274486 0.0 -0.734866228020307 -0.062 -0.062 0.008726849073962957 0.0 123.16666557966661 1.2292998660484957e-09 0.0 0.0 25619.0 Allies [-0.06088792 0.00475117 0.9981333 ] 0.5064766089927465 0.3371159370714128 0.6267890628740791 1.6191164404478644 -4.404605641298986 1.0085164509526248 0.9403428264947271 1.002228406356249 0.5911076156375097 0.04943091153402836 -0.12347543075231103 -0.031096345163790243 -0.1049357617938111 0.024866980145114622 0.04861966645392242"; RegexOptions options = RegexOptions.Multiline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx