Java笔记总结（四十七）---HashSet练习&添加三个元素，重复元素不添加

package MapTest;

import java.util.HashSet;
import java.util.Objects;

public class Test {
    public static void main(String[] args) {

        HashSet hashSet = new HashSet();
        hashSet.add(new test01("张三",12));
        hashSet.add(new test01("李四",14));
        hashSet.add(new test01("张三",12));

        System.out.println(hashSet);
    }
}
class test01{
    private String name;
    private int age;

    test01(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "test01{" +
                "name='" + name + ''' +
                ", age=" + age +
                '}';
    }

    //如果name和age的值相同，在计算hashcode的时候返回相同的值
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        test01 test01 = (test01) o;
        return age == test01.age && name.equals(test01.name);
    }

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

}

输出结果：
[test01{name=‘张三’, age=12}, test01{name=‘李四’, age=14}]