var ( mu sync.Mutex items []Product vatRate = 10.0 order Order ) type Product struct { NameOfProduct string PriceOfProduct float32 } type Order struct { Items []Product } func init() { items = make([]Product, 100) } func AddItemToShoppingCart(item Product) { items = append(items, item) } func RemoveItemFromShoppingCart(nameOfItem string) bool { mu.Lock() defer mu.Unlock() for i, item := range items { if item.NameOfProduct == nameOfItem { items = append(items[:i], items[i+1:]...) } } }