php中树形结构转数组（拉平树结构，保留上下级排序）

前言

在做php中树形结构转数组的功能中有时候需要把树结构直接拉平按照树结构的顺序按照由上到下排列，这时候就需要另外一种处理方法了。

解决办法

//树结构数据转数组（拉平树结构，保留上下级排序）
function treeToList($arr, $pid = 0)
{
    
    $array = array();
    foreach ($arr as $val) {
    
        $inData = array(
            "key" => $val["key"],
            "p_key" => $pid,
            "title" => $val["title"],
        );
        $array[] = $inData;
        if (isset($val["children"])) {
    
            $children = treeToList($val["children"], $val["key"]);
            if ($children) {
    
                $array = array_merge($array, $children);
            }
        }
    }
    return $array;
}

直接拉平树状结构，保留上下排序。

$tree = [
    [
        "key" => 1,
        "p_key" => 0,
        "title" => "湖北省",
        "children" => [
            [
                "key" => 2,
                "p_key" => 1,
                "title" => "武汉市",
                "children" => [
                    [
                        "key" => 3,
                        "p_key" => 2,
                        "title" => "武昌区",
                        "children" => [
                            [
                                "key" => 4,
                                "p_key" => 3,
                                "title" => "蛇山西山坡特1号",
                                "children" => [
                                    [
                                        "key" => 5,
                                        "p_key" => 4,
                                        "title" => "黄鹤楼",
                                    ],
                                ],
                            ],
                        ],
                    ],
                ],
            ],
        ],
    ],
];

$data = [
    [
        "key" => 1,
        "p_key" => 0,
        "title" => "湖北省",
    ],
    [
        "key" => 2,
        "p_key" => 1,
        "title" => "武汉市",
    ],
    [
        "key" => 3,
        "p_key" => 2,
        "title" => "武昌区",
    ],
    [
        "key" => 4,
        "p_key" => 3,
        "title" => "蛇山西山坡特1号",
    ],
    [
        "key" => 5,
        "p_key" => 4,
        "title" => "黄鹤楼",
    ],
];