Question

For single value check, which of both is preferred and why?

$string == 'The quick brown fox jumps over the lazy dog';

if(strpos($string, 'fox') !== false){
    // do the routine
}

# versus

if(preg_match('/fox/i', $string)){
    // do the routine
}

Answer 1

I would prefer the strpos over preg_match, because regexes are generally more expensive to execute.

According to the official php docs for preg_match:

Do not use preg_match() if you only
want to check if one string is
contained in another string. Use
strpos() or strstr() instead as they
will be faster.