<?php 
    function censorWords($text){ 

        $find = array( 
            '/damn/i', 
            '/shit/i', 
            '/fuck/i' 
        ); 
        $replace = array( 
            'dang', 
            'shoot', 
            'frick' 
        ); 
        return preg_replace($find,$replace,$text); 
    } 
    $text = 'That Damn cat is fucking stupid.'; 
    echo censorWords($text); 
?>