java-Map

• 实现Map接口的类用来存储键值对
• 键不能重复，值可以重复
• object put(object key,object value);
• object get(object key);
• object remove(object key);
• boolean containsValue(object value);
• boolean containsKey(object key);
• int size();
• boolean isEmpty();
• void putAll(Map t);
• void clear();

import java.util.*;public class Test5{   public static void main(String[] args)   {        Map m1 = new HashMap();        Map m2 = new TreeMap();        m1.put("one",1);        m2.put("two",2);        System.out.println(m1.size());    System.out.println(m1.containsKey("one"));   }}