Regular Expressions 101

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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 = @"({})\1|[{](|\s*?[^\s{}]+?\s*?|\s*?\S+?\(.*?\)\s*?|\s*?['][^']+?[']\s*?|\s*?[""][^""]+?[""]\s*?|\s*?[""][^""]+?[""]\.\S+?\(.*?\)\s*?|\s*?['][^']+?[']\.\S+?\(.*?\)\s*?)(?:!(\S+?))?[}]"; string input = @"{k} must-match {} jhtgj {} must-match { } not-match '""{firstName} {lastName}"" <{email}>' {0.concat(""8a b c d e"", 6)} must-match s df s sd{""one fielslkein 897sd'f8'97f 89s(*Y*&Sc {}d name"".toFixed(7 , 8)} must-match s df s sd{'one fielslkein ""897sd""f897f 89s(*Y*&Sc {}d name'.toFixed(7 , 8)} must-match sd{0.concat(""8a b c d e"", 6)} must-match ascdac{ ""one fieldname"" } must-match ascdac{ ""onefi eldname"".kk(kk, ""dd"") } must-match {onefieldname.toFixed(7 , 8)} must-match dfgsdg { ""onefieldname"".toFixed(7 , 8)} must-match {onefieldname: ""toFixed(7 , 8)""} not-match {""onefieldname"": ""toFixed(7 , 8)""} not-match { ""onefiel dname"" : ""toFixed(7 , 8)""} not-match { ""onefiel dname"": 8} not-match { ""o dna"" : {onefi eldname.l(7 , 8)} } not-match { ""o dna"" : {""onefi eldname"".l(7 , 8)} } match-inner { ""f dna"" : {""onefi eldname"".toFixed(7 , 8) }} match-inner { ""f dna"" : { ""onefi eldname"".toFixed(7 , 8) }} match-inner { ""o dme"" : {onefieldname.toFixed(7 , 8)} } match-inner { ""on dname"" : { onefieldname.toFixed(7 , 8)} } match-inner { {}: ""{}"" }"; 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