JAVA-2.2-homework

package Ac;

import java.util.*;

public class Test {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        show();
    }
    public static void show() {
    Map a = new HashMap();
    a.put("欧欧","Q仔");
    a.put("亚亚","Q妹");
    a.put("菲菲","Q妹");
    a.put("美美","Q妹");
    System.out.println("共计有"+a.size()+"只企鹅");
    Set keys = a.keySet();
    Iterator it = keys.iterator();    
    System.out.println("分别是：");
   while (it.hasNext()) {
       String key = (String)it.next();
       String b = (String) a.get(key);
       System.out.println(key+"\t"+b);
    }
    }
}

 

package Ac;

import java.util.*;

public class Test {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        show();
    }
    public static void show() {
        Map<String,String> a = new HashMap<String,String>();
        a.put("欧欧","Q仔");
        a.put("亚亚","Q妹");
        a.put("菲菲","Q妹");
        a.put("美美","Q妹");
        System.out.println("共计有"+a.size()+"只企鹅");
        System.out.println("iterator输出");
        //iterator输出
        Set<String> keys = a.keySet();
        Iterator<String> it = keys.iterator();    
        System.out.println("分别是：");
        while (it.hasNext()) {
            String key = (String)it.next();
            String b = (String) a.get(key);
            System.out.println(key+"\t"+b);
        }
        System.out.println("foreach语句输出");
        //foreach语句输出
        for (String key : keys) {
            String b = a.get(key);
            System.out.println(key+"\t"+b);
        }
    }
}