嵌套数组.第三层正在消失 [英] Nested array. Third level is disappearing

问题描述

我有那个数组:

$a = array(
    "7" => array(
        "id" => 7,
        "parent" => 6
    ),
    "6" => array(
        "id" => 6,
        "parent" => 5
    ),
    "5" => array(
        "id" => 5,
        "parent" => 4
    ),
    "4" => array(
        "id" => 4,
        "parent" => 0
    ),
    "3" => array(
        "id" => 7,
        "parent" => 2
    ),
    "2" => array(
        "id" => 7,
        "parent" => 1
    ),
    "1" => array(
        "id" => 7,
        "parent" => 0
    )
);

我想要的结果是:

$a = array(
    "4" => array(
        "id" => 4,
        "parent" => 0,
        array(
            "5" => array(
                "id" => 5,
                "parent" => 4,
                array(
                    "6" => array(
                        "id" => 6,
                        "parent" => 5,
                        array(
                            "7" => array(
                                "id" => 7,
                                "parent" => 6
                            )
                        )
                    )
                )
            )
        )
    ),
    "2" => array(
        "id" => 7,
        "parent" => 1,
        array(
            "3" => array(
                "id" => 7,
                "parent" => 2
            )
        )
    ),
    "1" => array(
        "id" => 7,
        "parent" => 0
    )
);

我使用的代码是这样的:

the code that I use is this :

foreach($a as $v)
{
    if(isset($a[$v['PARENT']]))
    {
        $a[$v['PARENT']][$v['ID']] = $v;
        unset($a[$v['ID']]);
    }
}

我遇到的问题是我得到了那个结果:

and the problem that I have is that I get that result :

$a = array(
    "4" => array(
        "id" => 4,
        "parent" => 0,
        array(
            "5" => array(
                "id" => 5,
                "parent" => 4
            )
        )
    ),
    "2" => array(
        "id" => 7,
        "parent" => 1,
        array(
            "3" => array(
                "id" => 7,
                "parent" => 2
            )
        )
    ),
    "1" => array(
        "id" => 7,
        "parent" => 0
    )
);

而不是需要它的结果.

推荐答案

要解决您的问题，您需要正确了解 PHP 中的变量引用/别名 有效.

To solve your problem you need to properly understand how variable referencing/aliasing in PHP works.

看看下面的示例代码，它看起来和你的没有太大区别，但利用引用来访问任何已经移动"的父级:

Look at the following example code, which does not look much different to yours but makes use of references in order to access any parent even it has already "moved":

# transform $flat into a tree:
foreach($flat as $id => &$value)
{
    # check if there is a parent
    if ($parentId = $value['parent'])
    {
        $flat[$parentId][0][$id] =& $value; # add child to parent
        unset($flat[$id]); # remove reference from topmost level
    }
}
unset($value); # remove iterator reference
print_r($flat); # your tree

$flat 现在包含来自 $flat 的所有值 - 但重新排序.演示.

$flat now contains all values from $flat - but reordered. Demo.

这篇关于嵌套数组.第三层正在消失的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！