HashMap在键值映射中的使用

代码实例：

import java.util.*;

public class demo6 { public static void main(String[] args) { Map map = new HashMap();

map.put("String", "这是一个字符串"); map.put("Object", new Object()); map.put("int", 1234); map.put("数字", 1234); map.put(1, "1"); map.put(new Object(), new Object()); map.put(null, null); System.out.println(map.size()); Set set = map.keySet(); Iterator it = set.iterator(); while (it.hasNext()) { Object obj = it.next(); System.out.println(obj + "：" + map.get(obj)); System.out.println(map.get("String" )); } }

}