读书笔记 == equals区别

参考：https://www.jianshu.com/p/9cbed9f33a4d

public class Test {
    public static void main(String[] args) {
        Book book1 = new Book("狮子王",77.09D);
        Book book2 = new Book("狮子王",77.09D);
        //Book book2 = book1;
        System.out.println(book1.hashCode());
        System.out.println(book2.hashCode());
        System.out.println(book1.equals(book2));
        System.out.println(book1==book2);
    }
    static class  Book{
        private String name;
        private Double price;

        public Book(String name, Double price) {
            this.name = name;
            this.price = price;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Book book = (Book) o;
            return Objects.equals(name, book.name) &&
                    Objects.equals(price, book.price);
        }

        @Override
        public int hashCode() {
            return Objects.hash(name, price);
        }
    }
}

78820460
78820460
true
false

基本类型只能==比较

引用类型不重写equals方法时 equals比较的是内存地址

重写时则按照重新规则判断

有相同的hashcode两个对象不一定==

new 对象内存地址肯定不相同

来源：CSDN

作者：清晨细雨~

链接：https://blog.csdn.net/dream_snow2012/article/details/103475146