用foreach和Iterator遍歷集合的方法

package TestMap;

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

/**
 * Created by Administrator on 2017/5/5.
 */
public class Main {
    public static void main(String[] args) {
        Map<Integer,Penguin> map = new HashMap<Integer,Penguin>();
        map.put(101,new Penguin("歐歐","Q仔"));
        map.put(102,new Penguin("丫丫","Q妹"));
        map.put(103,new Penguin("美美","Q妹"));
        map.put(104,new Penguin("菲菲","Q妹"));
        Set keys = map.keySet();
        System.out.println("foreach方法的遍歷結果爲：");
        for (Object key:keys) {
           Penguin value = (Penguin) map.get(key);
            System.out.println(key+" "+value.getName()+" "+value.getSex());
        }
        System.out.println("Iterator方法的遍歷結果：");
        Iterator it = keys.iterator();
        while (it.hasNext()) {
            Integer key = (Integer) it.next();
            Penguin value = (Penguin) map.get(key);
            System.out.println(key+" "+value.getName()+" "+value.getSex());

        }

    }

}

package TestMap;

/**
 * Created by Administrator on 2017/5/5.
 */
public class Penguin {
    String name;
    String sex;
    public Penguin(String name,String sex){
        this.name=name;
        this.sex=sex;
    }
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }
}

運行結果：

foreach方法的遍歷結果爲：
101 歐歐 Q仔
102 丫丫 Q妹
103 美美 Q妹
104 菲菲 Q妹
Iterator方法的遍歷結果：
101 歐歐 Q仔
102 丫丫 Q妹
103 美美 Q妹
104 菲菲 Q妹