检测在php中替换哪个字符串

Question

Is it possible to tell which string or strings are replaced when using PHP's str_replace function?

In other words, I have a call similar to the following

$subject = str_replace($search, $replace, $subject, $count);

Where $search and $replace are both arrays. If $count > 0 I want to figure out which strings were replaced and do something with them. Is something like this possible? Is there a function which does it? Should I just rewrite my code?

Answer 1

A possible approach is array_diff()

$str = array('something to rplace', 'anything else', 'sth else', 'one more');
$str2 = $str;

$str = str_replace($search, $replace, $str, $count);

var_dump( array_diff($str2, $str) );