Question

我刚开始在Java中使用HashMaps，我想知道是否可以在HashMap中总结对象值。

我已经使用像这样的ArrayList完成了这个：

private int totalWeight() {
        int totalWeight = 0;
        for(Item item : items){
            totalWeight += item.getWeight();
        }
        return totalWeight;
    }

我有不同的对象与值权重，我试图将权重的总值返回为totalWeight，但似乎不能使用HashMap。

Answer 1

您可以尝试这样的事情

public class HMTest {

    public static void main(String[] args) {

        int totalWeight = 0;
        HashMap<String, Item> map = new HashMap<String, Item>();
        map.put("Key1", new Item(10));
        map.put("Key2", new Item(20));
        map.put("Key3", new Item(30));

        Collection<Item> values = map.values();

        for (Item i : values) {
            totalWeight += i.getWeight();
        }

        System.out.println("Total Weight :" + totalWeight);

    }

}

class Item {
    private int weight;

    public Item(int weight) {
        this.weight = weight;
    }

    public int getWeight() {
        return weight;
    }

    public void setWeight(int weight) {
        this.weight = weight;
    }

}

可以在HashMap中总结对象值吗？

1 个答案: