Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • 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

/
/
g

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"[A-Z](\w|')*\.?\s+([A-Z](\w|')*\.\s+|(\w|')*\s+|""[^""]*""\s+)*([A-Z](\w|')*\.|(\w|')*|""[^""]*"")(\.|[?!])"; string input = @"'Dr. T.G. Walker alarmed the whole 20.50 train when Mr. T.G. Walker got up shouting at 10 o'clock.' ""The exchange rate was at 500.72."" After the crowd dissipated the police also went home. 'Mr. Sherlock Holmes and Dr. John Watson and Mrs. Williams together with T.G. Hooker and Capt. Marshall, of course, were better than the F.B.I. at crime fighting. Feb. 20 Mr. Barack Obama vowed as a candidate before Rep. TestNameAbbreviation that he would put the U.S. on a path to addressing climate change A.S.A.P!!!!!!! Is that so? Unfortunately, yes. That is so. Truly? Is that true? Yes, it is true. Well, then! Yes that is so, A.S.A.P! Help us please! This is from I.T? Yes, it is. No, it is not. Y. Yea. Is that so, truly? Yes, that is so. Unfortunately it is..... Is that really the case, Anthony? Why yes, yes it is. Is that really the case? Really, is it, so? On Saturday, Sgt. Timothy said... Sgt. Timothy said ... It was I! For they are dead. Trailing punctuation test!!!!!! Test?!. Test?!. Test!? Test?! Test...test.... Harry, you're a 'wizard'. Yes, really. (this only splits because of |\S{4,}) New line one, which without ending punctuation, is not detected I would use |(?:[^\r\n]+) but this seems to break the regex New line three New line four, etc"; foreach (Match m in Regex.Matches(input, pattern)) { 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