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

/
/
iJxmg

Test String

Code Generator

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"^[^\S\r\n]* (?: \s* (?<section>\[[^\]]*\]) [^\S\r\n]* (?<comment>(?:[#;].*)?) | (?<comment>(?:[#;].*)?) | (?: (?<key>[^#;]+?) \s* = [^\S\r\n]* (?: (?: ""(?<value_quote>.*)"" | (?<value>(?:[^#;\r\n\\\s]*[\s]??(?:\\.)*)*) ) [^\S\r\n]* (?<comment>(?:[#;].*)?) ) ) | (?<error>.*) ) $"; string input = @";An orphan comment at the top of the file #Another orphan comment #Comment above a group [Group1] #Group comment 1 Key1=Value1#Comment 1 Key2=Value 2 Key 3=Value 3 Key 4=Value4 Key5=Value \#5;Comment 2 ;Another comment above a group [Group 2] ;Group comment 2 Key1 = Value1 #Comment 3 Key2 = Value 2 Key 3 = Value 3 Key 4 = Value4 Key 5 = Value\;5 ;Comment 4 Key 6 = Value\;6\#1 ;Comment 5 Key 7 ;Comment 6 Key 8 = Value;7 \\;Comment 7 Key 8 =;Comment 7 Key 9 = Value\\;8 ;Comment 8 ; with quotes ;An orphan comment at the top of the file #Another orphan comment #Comment above a group [Group1] #Group comment 1 Key1=""Value1""#Comment 1 Key2=""Value 2"" Key 3=""Value 3"" Key 4=""Value4"" Key5=""Value \#5"";Comment 2 ;Another comment above a group [Group 2] ;Group comment 2 Key1 = ""Value1"" #Comment 3 Key2 = ""Value 2"" Key 3 ="" Value 3"" Key 4 = ""Value4"" Key 5 = ""Value\;5 ;Comment 4"" Key 6 = ""Value\;6\#1 "";Comment 5 Key 7 ;Comment 6 Key 8 = ""Value;7 \"";Comment 7 Key 8 ="";Comment 7 Key 9 = ""Value\\"";8 ;Comment 8 "; RegexOptions options = RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | 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