PHP如何将普通数组转换为以object_type为键的多维数组

PHP数组按object_type字段分组实现方案 #

基础遍历实现（最适合初学者理解） #

直接遍历原数组，按object_type字段值分组即可，代码如下：

// $origin 为你的原数组变量
$result = [];
foreach ($origin as $item) {
    $result[$item['object_type']][] = $item;
}

转换后结构 #

执行上述代码后，$result就是你需要的多维数组，结构如下：

Array
(
    [1] => Array
        (
            [0] => Array
                (
                    [initiator_id] => 259
                    [object_type] => 1
                    [object_id] => 905
                    [date] => 2021-11-16 06:24:16
                )
            [1] => Array
                (
                    [initiator_id] => 259
                    [object_type] => 1
                    [object_id] => 905
                    [date] => 2021-11-16 04:54:54
                )
            [2] => Array
                (
                    [initiator_id] => 259
                    [object_type] => 1
                    [object_id] => 905
                    [date] => 2021-11-16 04:53:58
                )
        )
    [2] => Array
        (
            [0] => Array
                (
                    [initiator_id] => 219
                    [object_type] => 2
                    [object_id] => 915
                    [date] => 2021-11-16 04:53:58
                )
        )
)

逻辑说明 #

PHP支持动态创建数组键，不需要提前判断$result中是否存在对应object_type的键，遍历过程中如果对应键不存在会自动初始化空数组，再把当前项追加到数组末尾。

内容的提问来源于stack exchange，提问作者Roman