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
Processing...

Test String

Code Generator

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?s)Form.*?\K\d{9}(?=.*?FMLA)"; string input = @"Form ( For Medical Leaves of Absence ) DO NOT return this document with your original request for a leave of absence . Please email or fax this document to the HR Service Center 5 - 7 days before the date you're expected to return to work . SECTION I : To be completed by Associate Associate's Name : Associate's Job Title : Associate ID ; Location / Store # James Doe Garden Associate 123456789 SECTION II : To be completed by a health care provider treating the associate / patient : Your patient is currently on leave of absence . Answer , fully and completely , all applicable parts . Several questions seek a response as to the frequency or duration of a condition , treatment , etc. Your answer should be your best estimate based upon your medical knowledge 1 , experience , and examination of the patient . Be as specific as you can ; terms such as "" lifetime , "" or "" indeterminate "" may not be sufficient to determine FMLA coverage ."; 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