English string intercept function in PHP

1/**
2 * PHP Tutorial get string in english mix length
3 * @param $str string
4 * @param $ $charset string encoding
5 * @return return length, 1 Chinese = 1 bits, 2 english = 1 bits
6 */
7 function Strlength ($str, $charset = ' utf-8 ') {
8 if ($charset = = ' Utf-8 ') $str = Iconv (' utf-8 ', ' gb2312 ', $str);
9 $num = strlen ($STR);
$cnnum = 0;
for ($i =0; $i < $num; $i + +) {
if (Ord (substr ($str, $i +1,1)) >127) {
$cnnum + +;
$i + +;
15}
16}
$ennum = $num-($cnnum *2);
$number = ($ennum/2) + $cnnum;
return Ceil ($number);
20}
21st
22//test output length is 15
$str 1 = ' test test and test testing test ';
$str 2 = ' aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ';
$str 3 = ' AA Test AA Test AA test aaaaaa ';
Echo Strlength ($str 1, ' gb2312 ');
Echo Strlength ($str 2, ' gb2312 ');
Echo Strlength ($str 3, ' gb2312 ');