• ExHashSet

package ch02_set;

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

public class ExHashSet {

	public static void main(String[] args) {
		
		// HashSet<Member> hs = new HashSet<>();
		Set<Member> hs = new HashSet<>();
		
		Member memA = new Member("유재석", 50);
		Member memB = new Member("유재석", 50);
		System.out.println(memA.hashCode());
		System.out.println(memB.hashCode());
		
		hs.add(memA);
		hs.add(memB);
		hs.add(new Member("김종국",45));
		hs.add(new Member("김종국",45));
		System.out.println(hs);
		
		System.out.println("데이터 수 : " + hs.size());
		System.out.println();
		
		for(Member man : hs) {
			System.out.println(man);
		}
		System.out.println();
		
		Iterator<Member> it = hs.iterator();
		String dname = "유재석";
		while(it.hasNext()) {
			Member man = it.next();
			if(man.getName().equals(dname)) {
				System.out.println("찾았다...");
				it.remove();
			}
		}
		System.out.println();
		
		System.out.println(hs);
		
	}
}

• Member

package ch02_set;

public class Member {
	private String name;
	private int age;
	
	public Member(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;}
	
	public int hashcode() {
		return name.hashCode();
	}
	
	public boolean equals(Object obj) {
		if(obj instanceof Member) {
			Member tmp = (Member)obj;
			if(!name.equals(tmp.name)) {
				return false;
			}
			if(!(age == tmp.age)) {
				return false;
			}
			return true;
		}
		return false;
	}
	
	public String toString() {
		return name + " - " + age;
	}
	
}

• Person

package ch02_set;

public class Person {
	
	/*
	 * Person class 를 구현하세요
	 * → 이름, 전화번호의 관리가 가능합니다 
	 */
	private String name;
	private String phonenumber;
	
	public Person(String name, String phonenumber) {
		this.name=name;    this.phonenumber=phonenumber;
	}
	
	public int hashCode() { return name.hashCode() + phonenumber.hashCode(); }
	
	public String getname() {return name;}
	public void setname(String name) {this.name = name;}
	
	public String getphonenumber() {return phonenumber;}
	public void setphonenumber(String phonenumber) {this.phonenumber = phonenumber;}
	
	public boolean equals(Object obj) {
		if(obj instanceof Person) {
			Person tmp = (Person)obj;
			if(!name.equals(tmp.name))
				return false;
			if(!phonenumber.equals(tmp.phonenumber))
				return false;
			return true;
		}
		return false;
	}
	
	
	public String toString() {
		return name + " / " + phonenumber;
	}
}