请问下面的代码怎么理解

Question

$array=array("1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16","17","18","19","20");
$page=$_GET["page"];
$r=page($array,"5",$page);
$r=page($array,"5",$page);这行代码怎么理解呀？

Answer 1

page 是个自定义函数
你不给出处如何解释？

Answer 2

很显然，page()是个自定义的函数，要看page()函数的定义才能知道是怎么处理的。

Answer 3

你猜的真准、哈哈、就是个数组分页的东西、刚才那个page确实是个自定义函数
这个自定义函数里面有个
$prev=(($current-1)<=0 ? "1":($current-1));这种表达式里面的“？”号是什么意思呀、我以前书上看到过、

Answer 4

三元运算符。
$d=$a ? $b: $c; //如果$a为真则$d=$b否则等于$c