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

r"
"
gm

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"^(?:(http|https)://|//)?(?P<url>www.(?P<resource>facebook.com).*?/video.php\?.*?(?:(?:videos%2F(vb\.[0-9]+%2F)?|v%3D)(?P<id>[0-9]+)).*)"; string input = @"https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2Fbhonline%2Fvideos%2Fvb.214066990599%2F10154442915600600%2F%3Ftype%3D3&show_text=0&width=400 https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2Fbhonline%2Fvideos%2Fvb.214066990599%2F10154442915600600%2F%3Ftype%3D3&show_text=0&width=400 https://www.facebook.com/v2.7/plugins/video.php?app_id=113869198637480&channel=https%3A%2F%2Fstaticxx.facebook.com%2Fconnect%2Fxd_arbiter%2Fr%2FLJ9CfGDsgQ7.js%3Fversion%3D42%23cb%3Df2426abd38%26domain%3Ddevelopers.facebook.com%26origin%3Dhttps%253A%252F%252Fdevelopers.facebook.com%252Ff4a0a392c%26relation%3Dparent.parent&container_width=613&href=https%3A%2F%2Fwww.facebook.com%2Ffacebook%2Fvideos%2F10153231379946729%2F&locale=en_GB&sdk=joey&show_text=false&width=500 https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2Fthenewpaper%2Fvideos%2Fvb.39533052294%2F10154361380822295%2F%3Ftype%3D3&show_text=0&width=400"; 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