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

/
/
gimx

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?(DEFINE) (?<quote>['""]) (?<pair> (?> \w+ |(?: (?<pairQuote>(?&quote))[^'""]+?\k<pairQuote> ) ) \s*\: ) (?<string> (?<stringQuote>(?&quote))[\S\s]*?(?<!\\)\k<stringQuote> ) (?<integer>\-?\d+(?:\.\d+)?(?:e[-+]\d+)?) (?<scalar>true|false|null|(?&integer)) (?<elements> \s*(?&value) (?(R&array)|(?>(?:\s*\,(?&elements))|\s*)) ) (?<array>\[(?>(?&elements)|\s*)\]) (?<value> (?&object) |(?&string) |(?&scalar) |(?&array) ) (?<members> \s*(?&pair)\s*(?&value) (?(R&object)|(?>(?:\s*\,(?&members))|\s*)) ) (?<object>\{(?&members)?\}) ) \A(?&object)\Z"; string input = @"{""menu"": { ""header"": ""SVG Viewer"", ""items"": [ {""id"": ""Open""}, {""id"": ""OpenNew"", ""label"": ""Open New""}, null, {""id"": ""ZoomIn"", ""label"": ""Zoom In""}, {""id"": ""ZoomOut"", ""label"": ""Zoom Out""}, {""id"": ""OriginalView"", ""label"": ""Original View""}, null, {""id"": ""Quality""}, {""id"": ""Pause""}, {""id"": ""Mute""}, null, {""id"": ""Find"", ""label"": ""Find...""}, {""id"": ""FindAgain"", ""label"": ""Find Again""}, {""id"": ""Copy""}, {""id"": ""CopyAgain"", ""label"": ""Copy Again""}, {""id"": ""CopySVG"", ""label"": ""Copy SVG""}, {""id"": ""ViewSVG"", ""label"": ""View SVG""}, {""id"": ""ViewSource"", ""label"": ""View Source""}, {""id"": ""SaveAs"", ""label"": ""Save As""}, null, {""id"": ""Help""}, {""id"": ""About"", ""label"": ""About Adobe CVG Viewer...""} ], ""test"": [ ""Some value"", 4, null,{} ], ""empty_array"":[-0.34E+4] }}"; RegexOptions options = RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.IgnorePatternWhitespace; 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