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

/
/
g

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"Data Transfer Element (\d+):(Full|Empty)(?: \(Storage Element (\d+) Loaded\):VolumeTag = (\w+))?"; string input = @"Storage Changer /dev/sg2:2 Drives, 48 Slots ( 0 Import/Export ) Data Transfer Element 0:Full (Storage Element 2 Loaded):VolumeTag = ALF029L5 Data Transfer Element 1:Empty Storage Element 1:Full Storage Element 2:Empty Storage Element 3:Empty Storage Element 4:Full Storage Element 5:Full :VolumeTag=AEF812LV Storage Element 6:Full :VolumeTag=ALF021L5 Storage Element 7:Full :VolumeTag=ALF019L5 Storage Element 8:Full Storage Element 9:Full :VolumeTag=ALF035L5 Storage Element 10:Full :VolumeTag=AEF839LV Storage Element 11:Full :VolumeTag=ALF018L5 Storage Element 12:Empty Storage Element 13:Full :VolumeTag=AEF832LV Storage Element 14:Full :VolumeTag=ALF002L5 Storage Element 15:Full :VolumeTag=ALF020L5 Storage Element 16:Full :VolumeTag=ALF016L5 Storage Element 17:Full :VolumeTag=AEF831LV Storage Element 18:Full Storage Element 19:Full :VolumeTag=AEF814LV Storage Element 20:Full :VolumeTag=ALF010L5 Storage Element 21:Full :VolumeTag=ALF022L5 Storage Element 22:Full :VolumeTag=ALF001L5 Storage Element 23:Full :VolumeTag=AEF830LV Storage Element 24:Full :VolumeTag=ALF008L5 Storage Element 25:Full :VolumeTag=ALF038L5 Storage Element 26:Full Storage Element 27:Full :VolumeTag=ALF034L5 Storage Element 28:Full :VolumeTag=ALF009L5 Storage Element 29:Full :VolumeTag=AEF821LV Storage Element 30:Full :VolumeTag=ALF013L5 Storage Element 31:Full :VolumeTag=AEF822LV Storage Element 32:Full :VolumeTag=ALF006L5 Storage Element 33:Full :VolumeTag=ALF028L5 Storage Element 34:Full :VolumeTag=AEF813LV Storage Element 35:Full :VolumeTag=ALF007L5 Storage Element 36:Full :VolumeTag=ALF012L5 Storage Element 37:Full :VolumeTag=ALF005L5 Storage Element 38:Full :VolumeTag=ALF027L5 Storage Element 39:Full :VolumeTag=ALF025L5 Storage Element 40:Full :VolumeTag=AEF823LV Storage Element 41:Full :VolumeTag=ALF036L5 Storage Element 42:Full :VolumeTag=ALF017L5 Storage Element 43:Full :VolumeTag=AEF811LV Storage Element 44:Full :VolumeTag=AEF810LV Storage Element 45:Full :VolumeTag=ALF024L5 Storage Element 46:Full :VolumeTag=ALF003L5 Storage Element 47:Full :VolumeTag=ALF032L5 Storage Element 48:Full :VolumeTag=ALF039L5 "; 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