HashSet学习自测题

输出在最后

import java.util.HashSet;

import org.junit.Test;
public class test3 {
@Test
public void arrayListTest(){
	HashSet set = new HashSet();
	// Person1 类已重写Hashcode、equals、toString方法
	Person1 p1 =new Person1("A",10);
	Person1 p2 =new Person1("B",20);
	set.add(p1);
	set.add(p2);
	System.out.println(set);//输出？
	
	p1.name="C";
	System.out.println(set);//输出？
	set.remove(p1);
	System.out.println(set);//输出？
	set.add(new Person1("C",10));
	System.out.println(set);//输出？
	set.add(new Person1("A",10));
	System.out.println(set);//输出？
	
}

}

class Person1 {
	 String name;
	 int age;

	@Override
	public String toString() {
		return "Person1 [name=" + name + ", age=" + age + "]";
	}

	public Person1(String name, int age) {
		super();
		this.name = name;
		this.age = age;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + age;
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Person1 other = (Person1) obj;
		if (age != other.age)
			return false;
		if (name == null) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		return true;
	}
}

/*输出：
	 * [Person1 [name=A, age=10], Person1 [name=B, age=20]]
[Person1 [name=C, age=10], Person1 [name=B, age=20]]
[Person1 [name=C, age=10], Person1 [name=B, age=20]]
[Person1 [name=C, age=10], Person1 [name=C, age=10], Person1 [name=B, age=20]]
[Person1 [name=C, age=10], Person1 [name=A, age=10], Person1 [name=C, age=10], Person1 [name=B, age=20]]

	 */