來自：樹雄
時間：Sat 2018-07-07 20:32:01
來自：ywsing0
時間：Sat 2018-07-07 19:54:09koala can u answer xd
$a=1; $b=2; $c=&$b; $d=++$c; echo $a+$b+$c+$d;
Should be 10.
No machine at hand to really test it. But,
$a = 1; (a=1, b=null, c=null, d=null)
$b = 2; (a=1, b=2, c=null, d=null)
$c = &$b; (a=1, b=2, c=&b=2, d=null)
$d = ++$c; (a=1, b=3, c=&b=3, d=3)