Java HashMap

public class HashMapTest {

public static void main(String[] args) {

HashMap<String, Integer> m = new HashMap<String, Integer>();

m.put("김민철", 100);

m.put("민철", 200);

m.put("철", 300);

//키 존재여부 판단

System.out.println(m.containsKey("김민철2"));

//키값얻기

Integer a = m.get("김민철");

System.out.println(a);

//키 모두 얻기

Set keys = m.keySet();

Iterator<String> it = keys.iterator();

while (it.hasNext()) {

String key = it.next();

Integer i = m.get(key);

System.out.println(key + "===" + i);

}

}

}