Function to get the length of a UTF8 encoded string

/*
* Program for UTF8 encoding
* Get the length of the string, one Chinese represents 3 lengths
*/
function utf8_strlen($str) {
$count = 0 ;
for($i = 0; $i < strlen($str); $i++){
$value = ord($str[$i]);
if($value > 127) {
$count++ ;
if($value >= 192 && $value <= 223) $i++;
elseif($value >= 224 && $value <= 239) $i = $i + 2;
elseif($ value >= 240 && $value <= 247) $i = $i + 3;
else die('Not a UTF-8 compatible string');
}
$count++;
}
return $count;
 }
?>