[php] 變更陣列元素的順序

function change($buff,$new,$old){   
    $start = $old;
    $end   = $new;
    $keys   = array_keys($buff);
    $tmp    = $keys[$old];
    if($new==$old){
        return $buff;
    }elseif($new<$old){
        while($start>=$end){
            if($start>$end){
                $keys[$start] = $keys[($start-1)];
            }elseif($start==$end){
                $keys[$start] = $tmp;
            } 
           $start--;
        } 
   }elseif($new>$old){ 
       while($start<=$end){
            if($start<$end){
                $keys[$start] = $keys[($start+1)];
            }elseif($start==$end){
                $keys[$start] = $tmp;
            }
            $start++;
        }    }
    foreach($keys as $key =>$value){ 
       $NEW[$value] = $buff[$value]; 
   }
    return $NEW;
}

 
=======
範例：
$Buff['a']  = "A";
$Buff['b']  = "B";
$Buff['c']  = "C";
$Buff['d']  = "D";
$Buff['e']  = "E";
$Buff['f']  = "F";
$Buff['h']  = "H";
$Buff['i']  = "I";
$Buff['j']  = "J";
$Buff['k']  = "K";
$Buff['l']  = "L";

echo "

";

print_r($Buff);

print_r(change($Buff,6,3));

print_r(change($Buff,2,7));

echo "

";