(PECL ds >= 1.0.0)
Ds\Stack::copy — Returns a shallow copy of the stack
此函数没有参数。
Returns a shallow copy of the stack.
Example #1 Ds\Stack::copy() example
<?php
$a = new \Ds\Stack([1, 2, 3]);
$b = $a->copy();
// Updating the copy doesn't affect the original
$b->push(4);
print_r($a);
print_r($b);
?>
以上例程的输出类似于：
Ds\Stack Object
(
[0] => 3
[1] => 2
[2] => 1
)
Ds\Stack Object
(
[0] => 4
[1] => 3
[2] => 2
[3] => 1
)