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);
}
}
}