Useful regular expressions

Some useful PHP regular expressions: Find all emails in text:

preg_match_all('/([\s]*)[\._a-zA-Z0-9-]+@[\._a-zA-Z0-9-]+/i', $html, $matches);

Check that string is allowed to contain Cyrillic symbols, Latin symbols and numbers:

preg_match('/^[a-zA-Z\p{Cyrillic}\d\s\-]+$/u', $str);

Get anchors URLs in HTML:

preg_match_all("/<a\s[^>]*href=(\"??)([^\" >]*?)\\1[^>]*>(.*)<\/a>/siU", $html, $matches); 

Get src, title and alt of an image tag:

preg_match_all('/(src|title|alt)=("[^"]*")/i', $html, $matches);

Replace multiple intervals with single one:

preg_replace('!\s+!', ' ', $string); 

Replace anything but letters of any alphabet, spaces and numbers:

preg_replace('/[^ \w]+/u', '', $str); 

Search for a string in array of values: preg_grep("/{$search}/i", $array); To be continued...