package ch10.collection.Map;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

public class Ex02 {
	public static void main(String[] args) {
		HashMap<String, String> map=new HashMap<String, String>();
		map.put("JAVA", "자바");
		map.put("JSP", "웹프로그래밍");
		map.put("Oracle", "데이터베이스");
		map.put("Python", "머신러닝");
		
		System.out.println(map.toString());
		
		Set<String> set=map.keySet();	//key값만 출력, index(순서)값이 없기에 for문을 사용 할 수 없음
		System.out.println(set.toString());
		
		Iterator<String> iter=set.iterator();	//하나의 key값을 출력
		while(iter.hasNext()) {
			//System.out.println(iter.next());
			
			String value=map.get(iter.next());
			System.out.println(value);
		}
		
		System.out.println("\\n\\n ===========================");
		
		HashMap<String, Integer> hash=new HashMap<String, Integer>();
		hash.put("one", 66);
		hash.put("two", 77);
		hash.put("three", 88);
		
		System.out.println(hash.toString());
		System.out.println(hash.get("one"));
		
		Set<String> s=hash.keySet();
		System.out.println(s.toString());
		
		Iterator<String> i=s.iterator();
		while(i.hasNext()) {
			//System.out.println(i.next());
			
			int value2=hash.get(i.next());
			System.out.println(value2);
		}
	}

}

{JAVA=자바, JSP=웹프로그래밍, Oracle=데이터베이스, Python=머신러닝}
[JAVA, JSP, Oracle, Python]
자바
웹프로그래밍
데이터베이스
머신러닝

 ===========================
{one=66, two=77, three=88}
66
[one, two, three]
66
77
88