java - Java中查找最大值的所有者

Question

尝试一些java代码，我想找到最喜欢的东西的狗。本质上，是对每只狗的 favThings 值进行比较。我尝试了以下方法，但没有成功。此外，如果您能分享一些关于以下内容的建议，那就太棒了，因为我是 Java 新手。

public class Dog {
    String breed;
    boolean hasOwner;
    int age;
    int favThings;
    public Dog(String dogBreed, boolean dogOwned, int dogYears, int things) {
        breed = dogBreed;
        hasOwner = dogOwned;
        age = dogYears;
        favThings = things;
    }
    public static void main(String[] args) {
        Dog fido = new Dog("poodle", false, 4, 31);
        Dog nunzio = new Dog("shiba inu", true, 12, 3);
        Dog las = new Dog("Collie", true, 5, 4);
        System.out.println("The dog with the most fav things is " + max(Dog.favThings));
    }
}

问题出在最后一行。为了获得最喜欢的东西的狗的名字，我写了: max(Dog.favThings) 这不是所需要的。

它返回的是:

Dog.java:35: error: cannot find symbol
    System.out.println("The dog with the most fav things is "+ max(Dog.favThings));
                                                               ^
  symbol:   method max(int)
  location: class Dog
2 errors

Answer 1

您可能必须将所有 Dog 实例放入列表中，然后使用允许指定自定义比较器的流 max(..) 方法:

public static void main(String[] args) {
    Dog fido = new Dog("poodle", false, 4, 31);
    Dog nunzio = new Dog("shiba inu", true, 12, 3);
    Dog las = new Dog("Collie", true, 5, 4);

    List<Dog> list = new ArrayList<>();
    list.add(fido);
    list.add(nunzio);
    list.add(las);

    // We use a custom comparator that compares two Dog instances 'a' and 'b' based on the favThings field:
    Dog maxDog = Collections.max(list, (a,b) -> Integer.compare(a.favThings, b.favThings));

    System.out.println("The dog with the most fav things is " + maxDog.breed);
}