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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

/
/
g

Test String

Code Generator

Generated Code

#include <StringConstants.au3> ; to declare the Constants of StringRegExp #include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate Local $sRegex = "<p>(\s*)(<a(.*)>)?(\s*)(https?:\/\/)?(w{3}\.)?(youtube\.com|youtu\.be)\/(watch\?v=|embed\/)?([A-Za-z0-9-_]{11})(\S*)(\s*)(<\/a>)?(\s*)<\/p>" Local $sString = "No protocol:" & @CRLF & _ "" & @CRLF & _ "<p>youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "<p>www.youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "" & @CRLF & _ "HTTP or HTTPS:" & @CRLF & _ "" & @CRLF & _ "<p>http://youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "<p>http://www.youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "<p>https://youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "" & @CRLF & _ "With or without “www”" & @CRLF & _ "" & @CRLF & _ "<p>https://youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "" & @CRLF & _ "Youtu.be short links" & @CRLF & _ "<p>youtu.be/LQaehcfXvK0</p>" & @CRLF & _ "<p>https://youtu.be/LQaehcfXvK0</p>" & @CRLF & _ "" & @CRLF & _ "Embed Urls:" & @CRLF & _ "<p>http://www.youtube.com/embed/dQw4w9WgXcQ</p>" & @CRLF & _ "" & @CRLF & _ "URLs with extra parameters:" & @CRLF & _ "<p>https://www.youtube.com/watch?v=LQaehcfXvK0&feature=youtu.be</p>" & @CRLF & _ "<p>https://www.youtube.com/watch?v=dQw4w9WgXcQ&list=RDdQw4w9WgXcQ&start_radio=1&t=1</p>" & @CRLF & _ "" & @CRLF & _ "This URL won’t actually work on YouTube, but it works here, which is somewhat odd? And yet doesn't seem harmful." & @CRLF & _ "<p>youtu.be/embed/dQw4w9WgXcQ</p>" & @CRLF & _ "" & @CRLF & _ "Paragraph tags on separate lines with arbitrary whitespace:" & @CRLF & _ "" & @CRLF & _ "<p>" & @CRLF & _ " www.youtube.com/embed/u8pCsfT1gDU" & @CRLF & _ "</p>" & @CRLF & _ "" & @CRLF & _ "<p>" & @CRLF & _ " https://youtube.com/watch?v=dQw4w9WgXcQ" & @CRLF & _ "</p>" & @CRLF & _ "<p>" & @CRLF & _ " http://www.youtube.com/embed/dQw4w9WgXcQ" & @CRLF & _ "</p>" & @CRLF & _ "" & @CRLF & _ " <p>" & @CRLF & _ " youtube.com/watch?v=dQw4w9WgXcQ" & @CRLF & _ "" & @CRLF & _ "</p>" & @CRLF & _ "" & @CRLF & _ "Paragraph tags with any other text in them, besides the URL:" & @CRLF & _ "" & @CRLF & _ "<p>This shouldn’t work: https://youtube.com/watch?v=dQw4w9WgXcQ</p>" & @CRLF & _ "<p>https://youtube.com/watch?v=dQw4w9WgXcQ nor this</p>" & @CRLF & _ "<p>" & @CRLF & _ "https://youtube.com/watch?v=dQw4w9WgXcQ also not this" & @CRLF & _ "" & @CRLF & _ "</p>" & @CRLF & _ "" & @CRLF & _ "" & @CRLF & _ "Paragraph tags with links added by markdown-it:" & @CRLF & _ "" & @CRLF & _ "<p><a href="https://www.youtube.com/watch?v=dQw4w9WgXcQ">https://www.youtube.com/watch?v=dQw4w9WgXcQ</a></p>" & @CRLF & _ "" & @CRLF & _ "<p>" & @CRLF & _ " <a href="https://www.youtube.com/watch?v=dQw4w9WgXcQ?something" class="something" id="whatever">" & @CRLF & _ " youtube.com/watch?v=dQw4w9WgXcQ?foo=bar&whatever" & @CRLF & _ "" & @CRLF & _ " </a>" & @CRLF & _ "</p>" & @CRLF & _ "" Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH) Local $aFullArray[0] For $i = 0 To UBound($aArray) -1 _ArrayConcatenate($aFullArray, $aArray[$i]) Next $aArray = $aFullArray ; Present the entire match result _ArrayDisplay($aArray, "Result")

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 AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm