hashmaptest.java

孙鑫JAVA从入门到精通配套练习程序。所有程序都实际运行过

import java.util.*;
class HashMapTest
{
	public static void printElements(Collection c)
	{
		Iterator it = c.iterator();
		while(it.hasNext())
		{
			System.out.println(it.next());
		}
	}
	public static void main(String[] args)
	{
		HashMap hm = new HashMap();
		hm.put("one", "zhangshan");
		hm.put("two", "lisi");
		hm.put("three", "wangwu");
		
		System.out.println(hm.get("one"));
		System.out.println(hm.get("two"));
		System.out.println(hm.get("three"));
		
		Set keys = hm.keySet();
		System.out.println("keys");
		printElements(keys);
		
		Collection c = hm.values();
		System.out.println("values");
		printElements(c);
		
		Set entry = hm.entrySet();
		Iterator it = entry.iterator();
		while(it.hasNext())
		{
			Map.Entry me = (Map.Entry)it.next();
			System.out.println(me.getKey() + ": " + me.getValue());
		}
		//printElements(entry);
		
		
		
		
	}
}