Laravel validation:当数组中的一个元素不存在时，如何将该元素标记为必需

use Illuminate\Support\Facades\Validator;

$validator = Validator::make($request->all(), [
    'element' => 'required',
]);

if ($validator->fails()) {
    return response()->json(['error' => $validator->errors()], 400);
}

use Illuminate\Support\Facades\Validator;

public function validateArray(Request $request)
{
    $validator = Validator::make($request->all(), [
        'element' => 'required',
    ]);

    if ($validator->fails()) {
        return response()->json(['error' => $validator->errors()], 400);
    }

    // 其他操作...

    return response()->json(['success' => true]);
}