字符串数组模拟购物车： 使用学过的技术：统计购物车中每种商品及购买的数量： String[]goods={"跑鞋","牛奶","跑鞋","泡面","果啤","牛奶","泡面","牛奶","牙刷","电脑"} 跑鞋-2 牛奶-3

跑鞋-2 牛奶-3 泡面-2 果啤-1 牙刷-1 电脑-1

代码实现：

public class ShoppingCart {
    public static void main(String[] args) {
        String[] goods = {"跑鞋", "牛奶", "跑鞋", "泡面", "果啤", "牛奶", "泡面", "牛奶", "牙刷", "电脑"};
        Map<String, Integer> cart = new HashMap<>();
        for (String good : goods) {
            if (cart.containsKey(good)) {
                cart.put(good, cart.get(good) + 1);
            } else {
                cart.put(good, 1);
            }
        }
        for (Map.Entry<String, Integer> entry : cart.entrySet()) {
            System.out.println(entry.getKey() + "-" + entry.getValue());
        }
    }
}

输出结果：

跑鞋-2
电脑-1
果啤-1
泡面-2
牙刷-1
牛奶-3