import java.util.HashMap;import java.util.Map;import java.util.Set;//Map(映射)集合 
     <键，值>
      public class MapTest {    public static void main(String[] args) {        Map map = new HashMap();        //1.增加元素        map.put(101,"金庸");        map.put(102,"古龙");        map.put(103,"倪匡");        map.put(104,"蔡澜");        System.out.println(map);        System.out.println("2-------------------------");        //2.查找元素        Object m = map.get(102);        System.out.println(m);        System.out.println("3-------------------------");        //3.修改元素        map.replace(102,"古龙","黄霑");        System.out.println(map);        System.out.println("4-------------------------");        //4.删除元素        map.remove(104);        System.out.println(map);        map.remove(103,"倪匡");        System.out.println(map);        System.out.println("5--------------------------");        //5.查找所有键和值        Object key = map.keySet();        System.out.println(key);        Object value = map.values();        System.out.println(value);        //6.删除所有键和值        map.clear();        System.out.println(map);    }}
     

运行结果

{101=金庸, 102=古龙, 103=倪匡, 104=蔡澜}2-------------------------古龙3-------------------------{
    101=金庸, 102=黄霑, 103=倪匡, 104=蔡澜}4-------------------------{
    101=金庸, 102=黄霑, 103=倪匡}{
    101=金庸, 102=黄霑}5--------------------------[101, 102][金庸, 黄霑]{}