How to check a partial similarity of two strings in PHP

Question

Is it any function in PHP that check the % of similarity of two strings?

For example i have:

$string1=\"Hello how are you doing\" 
$string2= \" hi,          


        

Answer 1

As it's a nice question, I put some effort into it:

$l1) {
        $t = $ar2;
        $ar2 = $ar1;
        $ar1 = $t;
    }

    //flip array 2, to make the words the keys
    $ar2 = array_flip($ar2);


    $maxwords = max($l1, $l2);
    $matches = 0;

    //find matching words
    foreach($ar1 as $word) {
        if (array_key_exists($word, $ar2))
            $matches++;
    }

    return ($matches / $maxwords) * 100;    
}
?>