Map集合的两种取出方式

import java.util.*;
class Test
{
    public static void main(String[] args)
    {
        Map<String, Integer> map = new HashMap<String, Integer>();

        map.put("fan", 23);
        map.put("peng", 45);
        map.put("cheng", 34);

        //获取键Set集合
        Set<String> keySet = map.keySet();
        
        Iterator<String> it = keySet.iterator();

        while(it.hasNext())
        {
            String keyString = it.next();
            System.out.println(keyString+"-"+map.get(keyString));

        }
    }
}

class Test
{
    public static void main(String[] args)
    {
        Map<String, String> map = new HashMap<String, String>();

        map.put("fan", "fan");
        map.put("peng", "peng");
        map.put("cheng", "cheng");
                //泛型的嵌套形式，关系是Map.Entry<K, V>类型
        Set<Map.Entry<String, String>> entrySet = map.entrySet();

        Iterator<Map.Entry<String, String>> it = entrySet.iterator();

        while(it.hasNext())
        {
            Map.Entry<String, String> entry = it.next();
            String key = entry.getKey();
            String value = entry.getValue();

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