字符串翻转

 1 function str_reverse($str){
 2     $r = array();
 3     $result = '';
 4     $encode = mb_detect_encoding($str, array('UTF8','GBK'));
 5     $len=mb_strlen($str, $encode);
 6     for($i=0;$i<$len;$i++){
 7         $r[] = mb_substr($str,$i,1,$encode);
 8     }
 9     while(($tmp = array_pop($r)) !== NULL){
10         $result .= $tmp;
11     }
12     return $result;
13 }
14 echo str_reverse('360安全卫士');