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

/
/
g

Test String

Substitution

Processing...

Code Generator

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?:\/\/(?:\\\n|[^\n])*\n)|(?:\/\*[\s\S]*?\*\/)|((?:R""([^(\\\s]{0,16})\([^)]*\)\2"")|(?:@""[^""]*?"")|(?:""(?:\?\?'|\\\\|\\""|\\\n|[^""])*?"")|(?:'(?:\\\\|\\'|\\\n|[^'])*?'))"; string substitution = @"\1"; string input = @"// /* /* This is a multi line comment // <- ignored since in a comment */ // ""abc"" word "" // This is a single line comment char cha1[] = ""This is a string containing a combination //"", cha2[] = ""This has /* a fake comment */ in it"", cha3[] = ""This is tough because of (ignore this //) \ line continueation"", cha4[] = ""Handle comments in strings with \"" escaped quotes\ and escaped escaped escapes \\""; // This is a single line comment \ continuing on the next line void main() { int chInt = '\\b\''; printf(""Hello world!""); cpp11_1(R""xy(""/**/)xy""); cpp11_2(R""(""/**/)""); cS(@""End at the right place\"" /*and ignore this */); return 0; } "; Regex regex = new Regex(pattern); string result = regex.Replace(input, substitution); } }

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