11章-练习17-Map的使用

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

/**
 * 练习17：使用练习1中的Gerbil类，将其放入Map中,将每个Gerbil的名字（例如Fuzzy或Spot）String(键)与每个Gerbil(值)关联起来。为keySet（）获取Iterator,使用它遍历Map，
 * 针对每个"键"查询Gerbil，然后打印出"键"，并让gerbil执行hop()
 */
public class Excrcise17 {


    public static void excr(Map<String, Gerbil> map) {

        Set<String> keySet = map.keySet();
        Iterator<String> it = keySet.iterator();
        while (it.hasNext()) {
            String key = it.next();
            Gerbil gerbil = map.get(key);
            System.out.print(key + " ");
            gerbil.hop();
        }
    }

    public static void main(String[] args) {

        Map<String, Gerbil> stringGerbilMap = new HashMap<String, Gerbil>();
        Gerbil gerbil1 = new Gerbil(1);
        Gerbil gerbil2 = new Gerbil(2);
        Gerbil gerbil3 = new Gerbil(3);
        Gerbil gerbil4 = new Gerbil(4);
        stringGerbilMap.put("Fuzzy", gerbil1);
        stringGerbilMap.put("Spot", gerbil2);
        stringGerbilMap.put("Bob", gerbil3);
        stringGerbilMap.put("Keven", gerbil4);
        excr(stringGerbilMap);

    }
}

class Gerbil {
    private int gerbilNumber;

    public Gerbil(int gerbilNumber) {
        this.gerbilNumber = gerbilNumber;
    }

    public void hop() {
        System.out.println(gerbilNumber+" hop hop ！");
    }
}

/* Output:
Bob 3 hop hop ！
Spot 2 hop hop ！
Keven 4 hop hop ！
Fuzzy 1 hop hop ！
*///:~