~~~
/**
* 獲取頭像存儲路徑
* @param type $uid 會員UID
* @return type
*/
function getAvatarPath($uid) {
$uid = abs(intval($uid)); //UID取整數絕對值
$uid = sprintf("%09d", $uid); //前邊加0補齊9位，例如UID為31的用戶變成 000000031
$dir1 = substr($uid, 0, 3); //取左邊3位，即 000
$dir2 = substr($uid, 3, 2); //取4-5位，即00
$dir3 = substr($uid, 5, 2); //取6-7位，即00
return 'avatar/' . $dir1 . '/' . $dir2 . '/' . $dir3 . '/';
}
~~~
var_dump(getAvatarPath('1256'));
**輸出如下：**
> string(17) "avatar/000/00/12/"
