HashMap的用法（兩種迭代方法案例）

package TestMap;
import java.util.*;
/**
 * Created by Administrator on 2017/5/5.
 */
public class Testpet {
    public static void main(String[] args) {
        Map pets = new HashMap();
        pets.put("旺旺", "企鵝");
        pets.put("歐歐", "雪瑞娜");
        pets.put("湯姆", "貓");
        pets.put("傑瑞", "老鼠");
        Set keys = pets.keySet();
       /*  迭代輸出方法一
           Iterator it = keys.iterator();
           while (it.hasNext()) {
            String key = (String) it.next();
            String value = (String) pets.get(key);
            System.out.println(key + "\t\t" + value);
        }*/
       //方法二
        for (Object key:keys) {
            String value = (String) pets.get(key);
            System.out.println(key+"    "+value);
        }
    }

}

運行結果：

傑瑞    老鼠 旺旺    企鵝 歐歐    雪瑞娜 湯姆    貓