关于HashMap的建值取向

下面的一个实例简单说明hashmap的用法

import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

public class testMap{

public static void main(String [] args){

HashMap emPhone = new HashMap ();

emPhone.put("1","111-222-3333");
emPhone.put("测试2","444-555-6666");
emPhone.put("测试3","777-888-9999");

Set keys = emPhone.keySet();//Set类可以获取HashMap对象的键。
Iterator keyIter = keys.iterator();
while(keyIter.hasNext()){
String nextName = (String)keyIter.next();
String phoneNum = (String)emPhone.get(nextName);
System.out.println(nextName + ":" + phoneNum);
}

String phoneName = (String)emPhone.remove("测试3");
System.out.println("Removed 1's number :" + phoneName);

HashMap newEmpPhone = new HashMap ();

newEmpPhone.putAll(emPhone);
int dirSize = newEmpPhone.size();
System.out.println("Created new phone directory with 哈哈哈哈" + dirSize + " numbers...");

phoneName = (String)newEmpPhone.get("测试3");
System.out.println("测试2's number in new director: " + phoneName);

}

}