从数组建立父子关系

Question

我们有一个随机类别列表，需要按照以下规则在JSON输出中进行排列-  一种。所有父类别应按字母顺序排序  b。每个父类别都应按字母顺序对其子类别进行排序  C。亲子关系可以是多层次的

deiconify

Answer 1

此代码将假定父级出现在子级元素之前。它将没有父ID的所有内容添加到输出数组（$out）的基中，否则调用递归函数addChild()。 （忘记了，所以添加了）将每个条目添加到现有子项时，它使用usort()来按字母顺序对条目进行排序。

这将检查每个节点并检查它是否是父节点，如果不是，还将检查该节点的任何子节点（如果有），等等...

function addChild ( $element, &$tree )   {
    foreach ( $tree as &$leaf )  {
        if ( $leaf['_id'] == $element['parent'] )   {
            $leaf['children'][] = $element;
            usort($leaf['children'], 
                function($a, $b) { 
                    return strcmp($a["name"], $b["name"]); 
                });
            break;
        }
        if ( isset($leaf['children']) ) {
            addChild($element, $leaf['children']);
        }
    }
}
$out = [];
foreach ( $data as $element )   {
    if ( empty($element['parent']) )  {
        $out[] = $element;
    }
    else    {
        // Look for parent
        addChild($element, $out);
    }
}

创建...

Array
(
    [0] => Array
        (
            [name] => Travel
            [parent] => 
            [_id] => 1
            [children] => Array
                (
                    [0] => Array
                        (
                            [name] => Air Travel
                            [parent] => 1
                            [_id] => 1212
                            [children] => Array
                                (
                                    [0] => Array
                                        (
                                            [name] => Insurance
                                            [parent] => 1212
                                            [_id] => 113412
                                        )

                                )

                        )

                    [1] => Array
                        (
                            [name] => Hotel
                            [parent] => 1
                            [_id] => 212
                        )

                )

        )

    [1] => Array
        (
            [name] => Businss Exp
            [parent] => 
            [_id] => 2
            [children] => Array
                (
                    [0] => Array
                        (
                            [name] => Taxes
                            [parent] => 2
                            [_id] => 34
                            [children] => Array
                                (
                                    [0] => Array
                                        (
                                            [name] => Licenses
                                            [parent] => 34
                                            [_id] => 111232
                                        )

                                    [1] => Array
                                        (
                                            [name] => Local Tax
                                            [parent] => 34
                                            [_id] => 34111
                                        )

                                )

                        )

                )

        )

)