小心 SplStack 模式是 LIFO（後進先出），而不是 FIFO（先進先出）
<?php
$stack = array();
array_push($stack,"orange");
array_push($stack,"banana");
array_push($stack,"apple");
array_push($stack,"raspberry");
var_dump($stack);
?>
// 結果
array (大小=4)
0 => 字串 'orange' (長度=6)
1 => 字串 'banana' (長度=6)
2 => 字串 'apple' (長度=5)
3 => 字串 'raspberry' (長度=9)
<?php
$stack = new SplStack();
$stack ->push('orange');
$stack ->push('banana');
$stack ->push('apple');
$stack->push('raspberry');
$stack->rewind();
while($stack->valid()){
var_dump($stack->current());
$stack->next();
}
?>
//結果
字串 'raspberry' (長度=9)
字串 'apple' (長度=5)
字串 'banana' (長度=6)
字串 'orange' (長度=6)
