<?php
$str = "The man drove in his car.Then <strong>the man walked to the boat.</strong>";
$keywords = array('boat','car'); $result = preg_replace("#<strong>.*?<\/strong>(*SKIP)(*FAIL)|\b($p)\b#i", "gokart", $str); echo $result;
PD9waHAKCiRzdHIgPSAiVGhlIG1hbiBkcm92ZSBpbiBoaXMgY2FyLlRoZW4gPHN0cm9uZz50aGUgbWFuIHdhbGtlZCB0byB0aGUgYm9hdC48L3N0cm9uZz4iOyAKJGtleXdvcmRzID0gYXJyYXkoJ2JvYXQnLCdjYXInKTsKJHAgPSBpbXBsb2RlKCd8JywgYXJyYXlfbWFwKCdwcmVnX3F1b3RlJywgJGtleXdvcmRzKSk7CiRyZXN1bHQgPSBwcmVnX3JlcGxhY2UoIiM8c3Ryb25nPi4qPzxcL3N0cm9uZz4oKlNLSVApKCpGQUlMKXxcYigkcClcYiNpIiwgImdva2FydCIsICRzdHIpOwplY2hvICRyZXN1bHQ7