PHP递归函数数据转换技巧

function buildTree($data, $parentId = 0) {
    $tree = [];
    foreach ($data as $item) {
        if ((int)$item['parent_id'] === (int)$parentId) {
            $children = buildTree($data, $item['id']);
            if (!empty($children)) {
                $item['children'] = $children;
            }
            $tree[] = $item;
        }
    }
    return $tree;
}

// 示例数据
$flatData = [
    ['id' => 1, 'parent_id' => 0, 'name' => '首页'],
    ['id' => 2, 'parent_id' => 0, 'name' => '产品'],
    ['id' => 3, 'parent_id' => 2, 'name' => '手机'],
    ['id' => 4, 'parent_id' => 2, 'name' => '电脑'],
    ['id' => 5, 'parent_id' => 3, 'name' => 'iPhone'],
];

$treeData = buildTree($flatData);
print_r($treeData);

function flattenTree($tree, $level = 0, &$result = [], $prefix = '') {
    foreach ($tree as $item) {
        $item['level'] = $level;
        $item['name_display'] = str_repeat('  ', $level) . $item['name'];
        $result[] = $item;

        if (!empty($item['children'])) {
            flattenTree($item['children'], $level + 1, $result, $prefix);
        }
    }
    return $result;
}