二维数组根据 pid 以及 id 变为无限极分类状的数组

谁践踏了优雅 2021-06-24 16:10 326阅读 0赞

if (!function_exists('pr')) { 
        /** * 测试用打印函数 * @param array $arr */
        function pr($arr)
        { 
            if ($arr) { 
                echo '<pre>';
                print_r($arr);
                echo '</pre>';
            } else { 
                echo 'pr数组为空！';
            }
        }
    
    }

将要转化的数组

$arr = [
        ['id'=>1,'pid'=>0,'name'=>'a'],
        ['id'=>2,'pid'=>1,'name'=>'b'],
        ['id'=>3,'pid'=>1,'name'=>'c'],
        ['id'=>4,'pid'=>2,'name'=>'d'],
        ['id'=>5,'pid'=>2,'name'=>'e'],
        ['id'=>6,'pid'=>3,'name'=>'f'],
        ['id'=>7,'pid'=>3,'name'=>'g'],
    ];

代码:

到这一步就可以了,但是今天遇见一家公司的面试题,要求去除所有 pid,所以自己有进一步做了一件事情

输出

Array
    (
        [id] => 1
        [name] => a
        [children] => Array
            (
                [0] => Array
                    (
                        [id] => 2
                        [name] => b
                        [children] => Array
                            (
                                [0] => Array
                                    (
                                        [id] => 4
                                        [name] => d
                                    )
    
                                [1] => Array
                                    (
                                        [id] => 5
                                        [name] => e
                                    )
    
                            )
    
                    )
    
                [1] => Array
                    (
                        [id] => 3
                        [name] => c
                        [children] => Array
                            (
                                [0] => Array
                                    (
                                        [id] => 6
                                        [name] => f
                                    )
    
                                [1] => Array
                                    (
                                        [id] => 7
                                        [name] => g
                                    )
    
                            )
    
                    )
    
            )
    
    )

转化为 json 输出

{ 
        "id": 1,
        "name": "a",
        "children": [
            { 
                "id": 2,
                "name": "b",
                "children": [
                    { 
                        "id": 4,
                        "name": "d"
                    },
                    { 
                        "id": 5,
                        "name": "e"
                    }
                ]
            },
            { 
                "id": 3,
                "name": "c",
                "children": [
                    { 
                        "id": 6,
                        "name": "f"
                    },
                    { 
                        "id": 7,
                        "name": "g"
                    }
                ]
            }
        ]
    }