php把全角数字转为半角数字

1. function getalabnum($fnum) 
2. { 
3.  $nums = array("０","１","２","３","４","５","６","７","８","９","＋","－","％","．"); 
4.  $fnums = "0123456789+-%."; 
5.  for($i=0;$i<count($nums);$i++){ 
6.   if($nums[$i]==$fnum) return $fnums[$i]; 
7.  }//开源代码phpfensi.com 
8.  return $fnum; 
9. } 
10. //实例应用 
11. echo getalabnum('６'); // 6