Adding Key-Value Pairs: public Object put(Object key, Object value) : HashMap « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. HashMap

import java.util.HashMap;
import java.util.Map;

public class MainClass {
  public static void main(String[] a) {

    Map map = new HashMap();
    map.put("key1", "value1");
    map.put("key2", "value2");
    map.put("key3", "value3");

    System.out.println(map);
  }
}

{key1=value1, key3=value3, key2=value2}