PHP：遍历数组？

发布于 2024-09-07 01:39:28 字数 873 浏览 1 评论 0原文

我想要一个函数搜索我的数组，并且返回所有子节点到特定节点。什么是最合适的方法是这样做？在这种情况下需要递归吗？

我之前构建了一些相当复杂的函数，这些函数在有或没有递归的帮助下通过多维数组进行迭代并重新排列它们，但是这个问题让我完全陷入困境，我不能只是解决它......

这是我的数组：

Array
(
    [1] => Array (
            [id] => 1
            [parent] => 0

        )

    [2] => Array (
            [id] => 2
            [parent] => 1
        )

    [3] => Array (
            [id] => 3
            [parent] => 2
        )
)

更新：

我想要获得的输出。抱歉这个不好的例子，但我会把它归咎于缺乏如何格式化我需要做的事情的知识:)

function getAllChildren($id) {
    // Psuedocode
    return $array;
}

getAllChildren(1); // Outputs the following:

Array
(
    [2] => Array (
            [id] => 2
            [parent] => 1
        )

    [3] => Array (
            [id] => 3
            [parent] => 2
        )
)

原文

I want a function that
searches through my array, and
returns all the
children to a specific node. What is
the most appropriate way to do this?
Will recursion be necessary in this case?

I have previously constructed a few quite complex functions that iterates with or without the help of recursion through multi-dimensional arrays and re-arranging them, but this problem makes me completely stuck and I can't just get my head around it...

Here's my array:

Array
(
    [1] => Array (
            [id] => 1
            [parent] => 0

        )

    [2] => Array (
            [id] => 2
            [parent] => 1
        )

    [3] => Array (
            [id] => 3
            [parent] => 2
        )
)

UPDATE:

The output which I want to get. Sorry for the bad example, but I'll blame it on lack of knowledge on how to format the stuff I need to do :)

function getAllChildren($id) {
    // Psuedocode
    return $array;
}

getAllChildren(1); // Outputs the following:

Array
(
    [2] => Array (
            [id] => 2
            [parent] => 1
        )

    [3] => Array (
            [id] => 3
            [parent] => 2
        )
)

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眼眸里的那抹悲凉 2024-09-14 01:39:28

$nodes = array( 1   => array (  'id'        => 1,
                                'parent'    => 0
                             ),
                2   => array ( 'id'         => 2,
                               'parent'     => 1
                             ),
                3   => array ( 'id'         => 3,
                               'parent'     => 2
                             )
                );


function searchItem($needle,$haystack) {
    $nodes = array();
    foreach ($haystack as $key => $item) {
        if ($item['parent'] == $needle) {
            $nodes[$key] = $item;
            $nodes = $nodes + searchItem($item['id'],$haystack);
        }
    }
    return $nodes;
}


$result = searchItem('1',$nodes);
echo '<pre>';
var_dump($result);
echo '</pre>';

searchItem() 函数的非递归版本：（

function searchItem($needle,$haystack) {
    $nodes = array();
    foreach ($haystack as $key => $item) {
        if (($item['parent'] == $needle) || array_key_exists($item['parent'],$nodes)) {
            $nodes[$key] = $item;
        }
    }
    return $nodes;
}

假设父节点/子节点的顺序，因此子节点不会包含在数组中，除非父节点已经存在）

$nodes = array( 1   => array (  'id'        => 1,
                                'parent'    => 0
                             ),
                2   => array ( 'id'         => 2,
                               'parent'     => 1
                             ),
                3   => array ( 'id'         => 3,
                               'parent'     => 2
                             )
                );


function searchItem($needle,$haystack) {
    $nodes = array();
    foreach ($haystack as $key => $item) {
        if ($item['parent'] == $needle) {
            $nodes[$key] = $item;
            $nodes = $nodes + searchItem($item['id'],$haystack);
        }
    }
    return $nodes;
}


$result = searchItem('1',$nodes);
echo '<pre>';
var_dump($result);
echo '</pre>';

Non-recursive version of the searchItem() function:

function searchItem($needle,$haystack) {
    $nodes = array();
    foreach ($haystack as $key => $item) {
        if (($item['parent'] == $needle) || array_key_exists($item['parent'],$nodes)) {
            $nodes[$key] = $item;
        }
    }
    return $nodes;
}

(assumes ordering of the parents/children, so a child node isn't included in the array unless the parent is already there)

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吻泪 2024-09-14 01:39:28

<?php
function searchItem($needle)
{
    foreach ($data as $key => $item)
    {
        if ($item['id'] == $needle)
        {
            return $key;
        }
    }
    return null;
}
?>

<?php
function searchItem($needle)
{
    foreach ($data as $key => $item)
    {
        if ($item['id'] == $needle)
        {
            return $key;
        }
    }
    return null;
}
?>

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