HashSet 与HashMap的遍历

package com.hongyewell.java;

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

public class CollectionTest {

public static void main(String[] args) {
    //HashSet
    HashSet hs = new HashSet();
    hs.add("miying");
    hs.add("hongyewell");
    //Iterator迭代器
    Iterator it = hs.iterator();
    while(it.hasNext()){
    System.out.println("遍历set集合...."+ it.next());
    }

    //HashMap   Map接口没有add()方法，放置元素通过put()方法
    HashMap hMap = new HashMap();
    hMap.put("1", "miying");
    hMap.put("2", "hongyewell");
    //将key转换为set集合
    Set keySet = hMap.keySet();
    //keySet遍历
    Iterator iter = keySet.iterator();
    while( iter.hasNext()){  
        String key = (String)iter.next();  
        String value = (String)hMap.get(key);  

        System.out.println("keySet遍历:"+key + "----" + value);  
    }  


  //entrySet遍历

    Set entrySet = hMap.entrySet();  
    Iterator iterator = entrySet.iterator();
    while( iterator.hasNext()){  
        Map.Entry entry = (Map.Entry)iterator.next();  
        String key = (String)entry.getKey();  
        String value = (String)entry.getValue();  

        System.out.println("entrySet遍历:"+key + "---" + value);  
    }  

}

}