如何以递归方式将层添加到数组PHP中的对象

Question

I have a bunch of objects tiered in an array, and want to recursively loop through them with PHP to add their corresponding tiers. How can I do that?

NOTE: The structure of the array could go much deeper than shown.

Array
(
    [0] => stdClass Object //should be tier 1
        (
            [name] => Object name
            [children] => Array
                (
                    [0] => stdClass Object //should be tier 2
                        (
                            [name] => Object name
                            [children] => Array
                                (
                                    [0] => stdClass Object //should be tier 3
                                        (
                                            [name] => Object name
                                            [children] => Array
                                                (
                                                )
                                        )
                                    [1] => stdClass Object //should be tier 3
                                        (
                                            [name] => Object name
                                            [children] => Array
                                                (
                                                )
                                        )
                                )
                        )
                    [1] => stdClass Object //should be tier 2
                        (
                            [name] => Object name
                            [children] => Array
                                (
                                    [0] => stdClass Object //should be tier 3
                                        (
                                            [name] => Object name
                                            [children] => Array
                                                (
                                                )
                                        )
                                )
                        )
                )
        )
    [1] => stdClass Object //should be tier 1
        (
            [name] => Object name
            [children] => Array
                (
                )
        )
)

Answer 1

The problem is actually quite straight forward.

You need to iterate over each level of the structure, setting the tier, and when you encounter a node with children, recursively call the same function, but increment the tier value.

I used json_decode to more easily create the stdClass objects for the example, which you can see working here: https://3v4l.org/oCJUV

<?php

function setTier(array $nodes, $tier = 1)
{
    return array_map(function ($node) use ($tier) {
        $node->tier = $tier;
        $node->children = setTier($node->children, $tier + 1);

        return $node;
    }, $nodes);
}

$structure = json_decode('
    [{
        "name": "a",
        "children": [{
            "name": "c",
            "children": [{
                "name": "e",
                "children": [{
                    "name": "g",
                    "children": []
                }]
            }, {
                "name": "f",
                "children": []
            }]
        }, {
            "name": "d",
            "children": [{
                "name": "h",
                "children": []
            }]
        }]
    }, {
        "name": "b",
        "children": []
    }]
');

$structure = setTier($structure);

print_r($structure); die;