Question

I figured out how to check an OR case, preg_match( "/(word1|word2|word3)/i", $string );. What I can’t figure out is how to match an AND case. I want to check that the string contains ALL the terms (case-insensitive).

Answer 1

It’s possible to do an AND match in a single regex using lookahead, eg.:

preg_match('/^(?=.*word1)(?=.*word2)(?=.*word3)/i', $string)

however, it’s probably clearer and maybe faster to just do it outside regex:

preg_match('/word1/i', $string) && preg_match('/word2/i', $string) && preg_match('/word3/i', $string)

or, if your target strings are as simple as word1:

stripos($string, 'word1')!==FALSE && stripos($string, 'word2')!==FALSE && stripos($string, 'word3')!==FALSE