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

/
/
gm

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?:<img|(?<!^)\G)\h*([-\w]+)=""([^""]+)""(?=.*?\/>)"; string input = @"<p>List of sample images.</p> <img src=""https://placehold.it/250x100.jpg"" width=""250"" height=""100"" alt=""Dimensions Set"" /> <img src=""https://placehold.it/250x100/99cc00/000.jpg?text=JPG"" alt=""JPG"" /><br> <img src=""https://placehold.it/250x100.gif?text=GIF"" alt=""GIF"" /><br> <img src=""https://placehold.it/250x100/ff6600/000.png?text=PNG"" alt=""PNG"" /><br> <img class=""no-ext"" src=""https://placehold.it/350x150?text=No Extension"" alt=""No Ext"" /><br> <img src=""https://placehold.it/250x100.png"" custom-attr=""custom1"" another-attr=""custom2"" /><br> <img class=""svg"" src=""https://upload.wikimedia.org/wikipedia/commons/0/02/SVG_logo.svg"" alt=""SVG"" /><br> <img class=""webp"" src=""https://gstatic.com/webp/gallery/1.webp"" width=""100"" alt=""webP"" /><br>"; 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