#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