自动递增父数组的PHP语法

<?php
// 初始化变量
$parentId = 0;
$data = [];

// 添加子数组到父数组
for ($i = 0; $i < 5; $i++) {
    $data[] = [
        'id' => $i + 1,
        'parentId' => $parentId,
        'name' => 'Item ' . ($i + 1)
    ];
    
    // 如果是每三个子数组，父ID递增
    if (($i + 1) % 3 == 0) {
        $parentId++;
    }
}

// 打印结果
print_r($data);
?>

Array
(
    [0] => Array
        (
            [id] => 1
            [parentId] => 0
            [name] => Item 1
        )

    [1] => Array
        (
            [id] => 2
            [parentId] => 0
            [name] => Item 2
        )

    [2] => Array
        (
            [id] => 3
            [parentId] => 0
            [name] => Item 3
        )

    [3] => Array
        (
            [id] => 4
            [parentId] => 1
            [name] => Item 4
        )

    [4] => Array
        (
            [id] => 5
            [parentId] => 1
            [name] => Item 5
        )
)