接口应用：内部比较器Comparable

r囧r小猫 2023-01-16 03:22 120阅读 0赞

## 接口应用：内部比较器Comparable ##

public interface Comparable {
        public int compareTo(Object obj);
    }

public class Book implements Comparable{
    
        private String bookName;
        private String author;
        private String publisher;
        private double price;
        @Override
        public int compareTo(Object obj) {
            Book other = (Book)obj;
            if (this.price>other.price){
                return 1;
            }else if (this.price< other.price){
                return -1;
            }else {
                return 0;
            }
        }
    
        public Book(){
        }
        public Book(String bookName,String author,String publisher,double price){
            this.bookName = bookName;
            this.author = author;
            this.publisher = publisher;
            this.price = price;
        }
    }

public class Person implements Comparable{
    
        private String name;
        private int age;
        public Person(){
        }
        public Person(String name,int age){
            this.name = name;
            this.age = age;
        }
        @Override
        public int compareTo(Object obj) {
            Person other = (Person) obj;
            return this.age- other.age;
        }
    }

public class Test {
        public static void main(String[] args) {
            Book book1 = new Book("倚天屠龙记","金庸","清华大学出版社",35);
            Book book2 = new Book("倚天屠龙记","金庸","清华大学出版社",31);
            int result = book1.compareTo(book2);
            System.out.println(result);
    
            Person person1 = new Person("张三",24);
            Person person2 = new Person("李四",24);
            result = person1.compareTo(person2);
            System.out.println(result);
        }
    }

运行结果如下：

![20210423183941624.png][]

[20210423183941624.png]: /images/20221022/24d23a5f5ced4660a3373f5cc4e411a9.png