利用LinkedList生成一副扑克牌

 import java.util.LinkedList;
 import java.util.Random;

 //自定义一个Poker类，用于存储扑克的信息（花色、数字）
 class Poker{
     String color;
     String numbers;

     public Poker(String color, String numbers) {
         this.color = color;
         this.numbers = numbers;
     }

     //重写toString方法
     @Override
     public String toString() {
         return color + numbers;
     }

 }

 public class Demo3 {
     public static void main(String[] args) {
         LinkedList pokers = CreatePoker();
         shufflePoker(pokers);
         showPoker(pokers);
     }

     //生成一副扑克牌
     public static LinkedList CreatePoker(){
         LinkedList list = new LinkedList();
         String[] color = {"红桃","黑桃","梅花","方块"};
         String[] numbers = {"A","2","3","4","5","6","7","8","9","10","J","Q","K"};
         for (int i = 0; i < numbers.length; i++) {
             for (int j = 0; j < color.length; j++) {
                 list.add(new Poker(color[j], numbers[i]));
             }
         }
         return list;
     }

     //将扑克牌信息打印
     public static void showPoker(LinkedList pokers){
         for (int i = 0; i < pokers.size(); i++) {
             System.out.print(pokers.get(i) + " ");
             //为什么等于9？因为等于0的话，i为0时，直接换行打印。等于9是0 ~ 9，就是每十张牌变换行一次
             if(i % 10 == 9){
                 System.out.println();
             }
         }
     }

     //洗牌
     public static void shufflePoker(LinkedList pokers){
         Random random = new Random();
         for (int i = 0; i < 100; i++) { //i < 10也行，只不过原则上越大，牌洗得越乱
             int index1 = random.nextInt(pokers.size());
             int index2 = random.nextInt(pokers.size());
             Poker poker1 = (Poker) pokers.get(index1);
             Poker poker2 = (Poker) pokers.get(index2);
             pokers.set(index1, poker2);
             pokers.set(index2, poker1);
         }
     }
 }