<!DOCTYPE html>
<html lang="he">
<head>
<meta charset="utf-8">
</head>
<body>
<?php
function get_first_different_character($s1, $s2, $encoding = 'UTF-8') {
return mb_strlen(
mb_strcut($s1, 0, strspn($s1 ^ $s2, "\0"), $encoding), $encoding
);
}
$s1 = 'פיתוח אפליקציה';
$s2 = 'פיתוח תוכנה';
$pos = get_first_different_character($s1, $s2);
echo "position $pos: characters: " . mb_substr($s1, $pos, 1) . " " .
mb_substr($s2, $pos, 1);
/*
run:
position 6: characters: א ת
*/
?>
</body>
</html>