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

/
/

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(&amp;)('.$Key.')([^0-9a-zA-Z_])"; string input = @"<?php // Сравниваем Куки с данными if ($_COOKIE['login'] == $admin_login AND $_COOKIE['password'] == md5($admin_pass)) { If (isset($_POST['submit'])){ $date=explode(""."", date(""d.m.Y"")); switch ($date[1]){ case 1: $m='января'; break; case 2: $m='февраля'; break; case 3: $m='марта'; break; case 4: $m='апреля'; break; case 5: $m='мая'; break; case 6: $m='июня'; break; case 7: $m='июля'; break; case 8: $m='августа'; break; case 9: $m='сентября'; break; case 10: $m='октября'; break; case 11: $m='ноября'; break; case 12: $m='декабря'; break; } $createdata = $date[0].'&nbsp;'.$m.',&nbsp;'.$date[2]; $useradd = 'Admin'; $name = $_POST['amess']; $useradd = $_POST['useradd']; $text = $_POST['mess']; $textkrat = $_POST['opisan']; $title = $_POST['title']; $description = $_POST['description']; $keyword = $_POST['keywords']; $url = $_POST['amessurl']; $tegs = $_POST['tegs']; ?>"; Match m = Regex.Match(input, pattern); 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