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);
	}
}

原文地址:https://www.cnblogs.com/wjchang/p/3671707.html