<?php
 
$badWords = array('palavra1', 'safgfsa', 'palavra2', 'palavra3', 'pal4');
 
$string = "A palavra1 é igual a palavra2 que é diferente da palavra3";
$p = array();
 
foreach(explode(' ', $string) as $v) {
	$v = str_replace([',', '.', ';', '?', '!', ':'], ['', '', '', '', '', ''], $v); // eliminar entropia, retirar pontuacao de acoprdo com a nossa lingua
	if(in_array($v, $badWords)) {
		$p[] = $v;
	}
}
 
$p = array_unique($p);
if(count($p) > 0) {
	echo "foram encontradas palavras\n";
	print_r($p);
}

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