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 = @"(?P<Element><(?P<TagName>[:_A-z][-.0-9:_A-z\xB7]*)(?:[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*[\x09\x0A\x0D\x20]*=[\x09\x0A\x0D\x20]*(?:""(?:[^<&""]|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));)*""|'(?:[^<&']|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));)*'))*[\x09\x0A\x0D\x20]*(?:>(?:(?:[^<&\]]|](?!]>))*(?:(?:(?P>Element)|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));|<!\[CDATA\[(?:[^\x01-\x08\x0B\x0C\x0E-\x1F\x5D]|](?!]>))*]]>|<\?[:_A-z][-.0-9:_A-z\xB7]*(?<!(?i:\?xml))(?:[\x09\x0A\x0D\x20]+(?:[^\x01-\x08\x0B\x0C\x0E-\x1F\x3F]|\?(?!>))*)?\?>|<!--(?:[^\x01-\x08\x0B\x0C\x0E-\x1F\x2D]|-(?!-))*-->)(?:[^<&\]]|](?!]>))*)*)<\/(?P=TagName)[\x09\x0A\x0D\x20]*|\/)>)|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));|<!\[CDATA\[(?:[^\x01-\x08\x0B\x0C\x0E-\x1F\x5D]|](?!]>))*]]>|<\?[:_A-z][-.0-9:_A-z\xB7]*(?<!(?i:\?xml))(?:[\x09\x0A\x0D\x20]+(?:[^\x01-\x08\x0B\x0C\x0E-\x1F\x3F]|\?(?!>))*)?\?>|<!--(?:[^\x01-\x08\x0B\x0C\x0E-\x1F\x2D]|-(?!-))*-->|<!DOCTYPE[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*(?:[\x09\x0A\x0D\x20]+(?:SYSTEM[\x09\x0A\x0D\x20]+(?:""[^""]*""|'[^']*')|PUBLIC[\x09\x0A\x0D\x20]+(?:""[\x0A\x0D\x20\x21\x23-\x25\x27-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*""|'[\x0A\x0D\x20\x21\x23-\x25\x28-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*')[\x09\x0A\x0D\x20]+(?:""[^""]*""|'[^']*')))?[\x09\x0A\x0D\x20]*(?:\[(?:(?:<!ELEMENT[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*[\x09\x0A\x0D\x20]+(?:EMPTY|ANY|\([\x09\x0A\x0D\x20]*#PCDATA(?:(?:[\x09\x0A\x0D\x20]*\|[\x09\x0A\x0D\x20]*[:_A-z][-.0-9:_A-z\xB7]*)*[\x09\x0A\x0D\x20]*\)\*|[\x09\x0A\x0D\x20]*\))|(?:(?P<choice>\([\x09\x0A\x0D\x20]*(?:[:_A-z][-.0-9:_A-z\xB7]*|(?P>choice)|(?P>seq))[?*+]?(?:[\x09\x0A\x0D\x20]*\|[\x09\x0A\x0D\x20]*(?:[:_A-z][-.0-9:_A-z\xB7]*|(?P>choice)|(?P>seq))[?*+]?)+[\x09\x0A\x0D\x20]*\))|(?P<seq>\([\x09\x0A\x0D\x20]*(?:[:_A-z][-.0-9:_A-z\xB7]*|(?P>choice)|(?P>seq))[?*+]?(?:[\x09\x0A\x0D\x20]*,[\x09\x0A\x0D\x20]*(?:[:_A-z][-.0-9:_A-z\xB7]*|(?P>choice)|(?P>seq))[?*+]?)*[\x09\x0A\x0D\x20]*\)))[?*+]?)[\x09\x0A\x0D\x20]*>|<!ATTLIST[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*(?:[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*[\x09\x0A\x0D\x20]+(?:CDATA|(?:ID(?:REFS?)?|ENTIT(?:Y|IES)|NMTOKENS?)|(?:NOTATION[\x09\x0A\x0D\x20]+\([\x09\x0A\x0D\x20]*[:_A-z][-.0-9:_A-z\xB7]*(?:[\x09\x0A\x0D\x20]*\|[\x09\x0A\x0D\x20]*[:_A-z][-.0-9:_A-z\xB7]*)*[\x09\x0A\x0D\x20]*\)|\([\x09\x0A\x0D\x20]*(?:[-.0-9:_A-z\xB7])+(?:[\x09\x0A\x0D\x20]*\|[\x09\x0A\x0D\x20]*(?:[-.0-9:_A-z\xB7])+)*[\x09\x0A\x0D\x20]*\)))[\x09\x0A\x0D\x20]+(?:#(?:REQUIRED|IMPLIED)|(?:#FIXED[\x09\x0A\x0D\x20]+)?(?:""(?:[^<&""]|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));)*""|'(?:[^<&']|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));)*')))*[\x09\x0A\x0D\x20]*>|(?:<!ENTITY[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*[\x09\x0A\x0D\x20]+(?:(?:""(?:[^%&""]|%[:_A-z][-.0-9:_A-z\xB7]*;|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));)*""|'(?:[^%&']|%[:_A-z][-.0-9:_A-z\xB7]*;|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));)*')|(?:SYSTEM[\x09\x0A\x0D\x20]+(?:""[^""]*""|'[^']*')|PUBLIC[\x09\x0A\x0D\x20]+(?:""[\x0A\x0D\x20\x21\x23-\x25\x27-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*""|'[\x0A\x0D\x20\x21\x23-\x25\x28-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*')[\x09\x0A\x0D\x20]+(?:""[^""]*""|'[^']*'))(?:[\x09\x0A\x0D\x20]+NDATA[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*)?)[\x09\x0A\x0D\x20]*>|<!ENTITY[\x09\x0A\x0D\x20]+%[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*[\x09\x0A\x0D\x20]+(?:(?:""(?:[^%&""]|%[:_A-z][-.0-9:_A-z\xB7]*;|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));)*""|'(?:[^%&']|%[:_A-z][-.0-9:_A-z\xB7]*;|&(?:[:_A-z][-.0-9:_A-z\xB7]*|#(?:[0-9]+|x[0-9a-fA-F]+));)*')|(?:SYSTEM[\x09\x0A\x0D\x20]+(?:""[^""]*""|'[^']*')|PUBLIC[\x09\x0A\x0D\x20]+(?:""[\x0A\x0D\x20\x21\x23-\x25\x27-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*""|'[\x0A\x0D\x20\x21\x23-\x25\x28-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*')[\x09\x0A\x0D\x20]+(?:""[^""]*""|'[^']*')))[\x09\x0A\x0D\x20]*>)|<!NOTATION[\x09\x0A\x0D\x20]+[:_A-z][-.0-9:_A-z\xB7]*[\x09\x0A\x0D\x20]+(?:(?:SYSTEM[\x09\x0A\x0D\x20]+(?:""[^""]*""|'[^']*')|PUBLIC[\x09\x0A\x0D\x20]+(?:""[\x0A\x0D\x20\x21\x23-\x25\x27-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*""|'[\x0A\x0D\x20\x21\x23-\x25\x28-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*')[\x09\x0A\x0D\x20]+(?:""[^""]*""|'[^']*'))|PUBLIC[\x09\x0A\x0D\x20]+(?:""[\x0A\x0D\x20\x21\x23-\x25\x27-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*""|'[\x0A\x0D\x20\x21\x23-\x25\x28-\x2F\x3A\x3B\x3D\x3F\x40_0-9A-z]*'))[\x09\x0A\x0D\x20]*>|<\?[:_A-z][-.0-9:_A-z\xB7]*(?<!(?i:\?xml))(?:[\x09\x0A\x0D\x20]+(?:[^\x01-\x08\x0B\x0C\x0E-\x1F\x3F]|\?(?!>))*)?\?>|<!--(?:[^\x01-\x08\x0B\x0C\x0E-\x1F\x2D]|-(?!-))*-->)|(?:%[:_A-z][-.0-9:_A-z\xB7]*;|[\x09\x0A\x0D\x20]+))*][\x09\x0A\x0D\x20]*)?>"; string input = @"<appointments> <event date=""03-05-02"" start-time=""09:00"" end-time=""10:00""> <type>Meeting</type> <title>Staff Meeting</title> <description>Weekly staff meeting</description> <location>Conference Room</location> <reminder status=""no""/> </event> <event date=""03-06-02"" start-time=""14:00"" end-time=""15:00""> <type>Interview</type> <title>Developer Interview</title> <description>Interview new developer candidate.</description> <location>Office</location> <reminder status=""yes"" interval=""15-min"" method=""ICQ""/> </event> <event date=""03-15-02"" start-time=""13:45"" end-time=""15:00""> <type>Dentist</type> <title>Root Canal</title> <description>Root canal on lower left molar.</description> <location>Dr. Scrivello's Office</location> <reminder status=""yes"" interval=""1-day"" method=""e-mail""/> </event> </appointments>"; 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