JAVA_HashSet

package com.kk.Collection;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

public class HashSetTest {
    public static void main(String[] args) {
        Set hashSet=new HashSet();
        hashSet.add(new Student(0,"kk"));
        hashSet.add(new Student(1,"mm"));
        hashSet.add(new Student(1,"mm"));//内存地址和值一样,Set将不会添加同样的对象
        Iterator it=hashSet.iterator();
        while(it.hasNext()){
            Student stu=(Student) it.next();
            System.out.println(stu.name);
        }
    }

    static class Student {
        int num;

        String name;

        public Student(int num, String name) {
            this.num = num;
            this.name = name;
        }

        @Override
        /**
         * 判断对象的内存地址是否一样
         */
        public int hashCode() {
            return num*name.hashCode();
        }

        @Override
        /**
         * 判断对象的值是否一样
         */
        public boolean equals(Object obj) {
            Student stu=(Student) obj;
            return this.num==stu.num && this.name.equals(stu.name);
        }
    }
}