java例程练习（Map接口及自动打包、解包）

import java.util.*; public class Test { public static void main(String[] args) { Map m1 = new HashMap(); Map m2 = new HashMap(); m1.put("one", 1); //m1.put("one",new Integer(1)); m1.put("two", 2); //m1.put("two",new Integer(2)); m1.put("three", 3); //m1.put("three",new Integer(3)); m2.put("A", 1); //m2.put("A", new Integer(1)); m2.put("B", 2); //m2.put("B", new Integer(2)); System.out.println(m1.size()); System.out.println(m1.containsKey("one")); System.out.println (m2.containsValue(1)); //(m2.containsValue(new Integer(1))); if(m1.containsKey("two")) { int i =(Integer)m1.get("two"); //int i = ((Integer)m1.get("two")).intValue(); System.out.println(i); } Map m3 = new HashMap(m1); m3.putAll(m2); System.out.println(m3); } }