从哈希表获取键的“设置”视图

/*来自 
 时代Java公众号*/

 

import java.util.Enumeration;

import java.util.Iterator;

import java.util.Hashtable;

import java.util.Set;

 

public class Main {

 

  public static void main(String[] args) {

    Hashtable ht = new Hashtable();

    ht.put("1","One");

    ht.put("2","Two");

    ht.put("3","Three");

   

    Set st = ht.keySet();

   

    System.out.println("Set created from Hashtable Keys contains :");

    Iterator itr = st.iterator();

    while(itr.hasNext())

      System.out.println(itr.next());

    st.remove("2");//nowjava - 时代Java 提供

   

    System.out.println(