Splstack它是如何工作的？为什么？

<?php
    $stack = new SplStack();

    $stack->add(0, 'one');
    $stack->add(1, 'two');
    $stack->add(2, '2015');

    echo "<pre>";
    print_r($stack);

When i run this code, all items are stored an property called dllist (i hope) and it's the expected result.

当我运行此代码时，所有项目都存储了一个名为dllist的属性（我希望），这是预期的结果。

SplStack Object
(
    [flags:SplDoublyLinkedList:private] => 6
    [dllist:SplDoublyLinkedList:private] => Array
        (
            [0] => one
            [1] => two
            [2] => 2015
        )

)

But i run the code below, works the same way that code above, why when i try, $stack[] = 'one'; why does not get an error? how php know that $stack[] = 'one'; should be stored in dllist?

但我运行下面的代码，工作方式与上面的代码相同，为什么当我尝试时，$ stack [] ='one';为什么不出错？ php如何知道$ stack [] ='one';应该存储在dllist中？

<?php
    $stack = new SplStack();

    $stack[] = 'one';
    $stack[] = 2015;
    $stack[] = 'two';

    echo "<pre>";
    print_r($stack);

I expected some errors like this statements:

我期待像这样的声明一些错误：

<?php

    $int = 2015;
    $int[] = 300; //Warning: Cannot use a scalar value as an array in 

    $str = 'foo';
    $str[] = 'foo'; //Fatal error: [] operator not supported for strings in

    $obj = new stdClass(); 
    $obj[] = 'new one'; //Fatal error: Cannot use object of type stdClass as array in 

1 个解决方案

#1

SplStack implements the interface ArrayAccess, causing the SplStack class to have array-features: http://php.net/manual/en/class.arrayaccess.php

SplStack实现接口ArrayAccess，导致SplStack类具有数组功能：http：//php.net/manual/en/class.arrayaccess.php