循环

'items' => $trade->items->map(function ($item) use (&$points_exchange_type) {
    if ($item->payment <= 0 && $item->pay_points > 0) {
        $points_exchange_type = 1;
    }

    return [
        'id' => $item->id,
        'item_num' => $item->item_num,
        'sku_image' => thumbnail($item->sku_image, 228),
        'sku_name' => $item->sku_name,
        'sku_price' => $item->sku_price,
        'spec_values' => $item->spec_values ?? [],
        'trade_id' => $item->trade_id,
        'pay_points' => $item->pay_points ?? '0',
        'payment' => $item->payment ?? '0',
    ];
}),