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

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"^([^,]*,){39}"""; string input = @",1414,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,""kepware~5~63CC97F2-5494-43F2-9F92-79A2BEF58D2A"",""5:39265338"",,1473800029,""2016-09-13 20:54:20.206 +0000 Tag=""MODBUS.ROBOT.Position_Base"" Value=""1414"" Quality=""good"" "",""RS5c kepware"",Kepware,"".206"",""1473800060.206"",,,20,13,54,september,20,tuesday,2016,0,,,""24.97.250.66"",kepware,1,,,""--_::._+_=""..""_=""""_=""""_"",,Kepware,Kepware,RS5c,,,,,,29,0,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,""1487.42566"",,""kepware~5~63CC97F2-5494-43F2-9F92-79A2BEF58D2A"",""5:39143140"",,1473798904,""2016-09-13 20:35:35.147 +0000 Tag=""OmronCJ.PLC1.Suply_conv.Belt_speed"" Value=""1487.42566"" Quality=""good"" "",""RS5c kepware"",Kepware,"".147"",""1473798935.147"",,,20,13,35,september,35,tuesday,2016,0,,,""24.97.250.66"",kepware,1,,,""--_::._+_=""...""_="".""_=""""_"",,Kepware,Kepware,RS5c,,,,,,29,0,, ,,,,,,,,,,,,,,,,,,,,,0,,,,,,,,,,,,,,""kepware~5~63CC97F2-5494-43F2-9F92-79A2BEF58D2A"",""5:39117933"",,1473798672,""2016-09-13 20:31:42.457 +0000 Tag=""MODBUS.ROBOT.Velocity_Sholder"" Value=""0"" Quality=""good"" "",""RS5cSplunk1 kepware"",Kepware,"".457"",""1473798702.457"",,,20,13,31,september,42,tuesday,2016,0,,,""24.97.250.66"",kepware,1,,,""--_::._+_=""..""_=""""_=""""_"",,Kepware,Kepware,RS5c,,,,,,29,0,, ,,,,,,,,,,,,,,,,,,,,,,,,,""1491.82166"",,,,,,,,,,""kepware~5~63CC97F2-5494-43F2-9F92-79A2BEF58D2A"",""5:39105700"",,1473798560,""2016-09-13 20:29:50.387 +0000 Tag=""OmronCJ.PLC1.Assy_conv.belt_speed"" Value=""1491.82166"" Quality=""good"" "",""RS5c kepware"",Kepware,"".387"",""1473798590.387"",,,20,13,29,september,50,tuesday,2016,0,,,""24.97.250.66"",kepware,1,,,""--_::._+_=""...""_="".""_=""""_"",,Kepware,Kepware,RS5c,,,,,,29,0,, ,,,,,,,,,,,,,,,,,,,,1605,,,,,,,,,,,,,,,""kepware~5~63CC97F2-5494-43F2-9F92-79A2BEF58D2A"",""5:39087971"",,1473798396,""2016-09-13 20:27:06.649 +0000 Tag=""MODBUS.ROBOT.Velocity_Max_Wrst3"" Value=""1605"" Quality=""good"" "",""RS5c "; 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