php如何按id分组

// 假设有一个包含多个对象的数组
$objects = [
    ['id' => 1, 'name' => 'Object 1'],
    ['id' => 2, 'name' => 'Object 2'],
    ['id' => 1, 'name' => 'Object 3'],
    ['id' => 3, 'name' => 'Object 4'],
    ['id' => 2, 'name' => 'Object 5'],
];

// 创建一个空数组用于存储按id分组后的结果
$groupedObjects = [];

// 遍历原始数组
foreach ($objects as $object) {
    $id = $object['id'];

    // 如果分组不存在，则创建一个空数组
    if (!isset($groupedObjects[$id])) {
        $groupedObjects[$id] = [];
    }

    // 将对象添加到相应的分组中
    $groupedObjects[$id][] = $object;
}

// 打印按id分组后的结果
foreach ($groupedObjects as $id => $group) {
    echo "Group $id:\n";
    foreach ($group as $object) {
        echo $object['name'] . "\n";
    }
    echo "\n";
}