3v4l.org

run code in 300+ PHP versions simultaneously
<?php $searchTerm = "abcd"; $replaceTerm = "XXXX"; $test=array("${searchTerm}/${searchTerm}_.${searchTerm}", "xay${searchTerm}", "asdasd/${searchTerm}.mp3", "${searchTerm}.", "blahahbasd${searchTerm}"); foreach ($test as $t) echo "$t => " . preg_replace("/(". preg_quote($searchTerm) . "([^_.])|". preg_quote($searchTerm) . "$)/x", preg_quote($replaceTerm) . "\${2}", $t) . "\n";

preferences:
49.48 ms | 402 KiB | 5 Q