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🥭本文内容：Java——“21点”扑克游戏系统（变量+循环）
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Java——对象和类案例代码详解
目录
⛳️ 一、扑克项目需求
⛳️ 二、游戏代码实现
⛳️ 三、系统循环效果展示
⛳️ 一、变量项目需求
编写“21点”1点扑克游戏（每个需求用一个测试类来完成测试）
需求一： 计算机随机地向用户发5张牌，如果牌的扑克总点数小於或等於21点，则用户赢；超过21点则计算机赢。游戏
注意类的系统循环没有参数的构造器随机产生一张牌，并且不会重复发牌。变量类模仿真实牌局的行为，可以用getValue方法从一副牌中重复抽取牌。
你的程序应该：
抽取一张牌；
向用户显示这张牌；
显示到目前为止已发牌的总点数
需求二： 为使程序更象真实的牌局，用户应该能与计算机互动玩牌。修改刚才的程序，计算机仍然抽取5张牌，不超过21点的是赢家，如果双方都不超过21点，则双方都不算赢，你的程序应该能准确地报告结果。
程序应该：
为用户和计算机抽牌；
向用户显示牌；
分别显示用户和计算机的当前总点数；
为使游戏更加有趣，每抽一张新牌时都要显示牌和总点数
需求三： 修改程序使用户可以选择是否抽牌，而规定计算机必须抽5张牌或直到牌的总点数大於等於21
需求四： 修改程序使得用户可以一直玩下去，并分别累计用户和计算机赢的牌局数。
⛳️ 二、代码实现
1、提供默认引用类Card类，代码如下：
package cn.bdqn.demo04 ;/** * Represents a playing card * @author Roger Garside/John Mariani * @version Last Rewritten: 16th Sept 1997 */import java.util.* ;public class Card { // Card Class Variables private static boolean initialised = false ; private static Random rand = new Random() ; private static boolean[][] dealt = new boolean[4][13] ; private static int noDealt ; // Card Instance Variables /* * the suit of the card (0 to 3) */ private int suit ; /* * the value of the card (0 to 12) */ private int value ; // Card Class Constants /** * Constant - Spades */ public static final int SPADES = 0 ; /** * Constant - Hearts */ public static final int HEARTS = 1 ; /** * Constant - Clubs */ public static final int CLUBS = 2 ; /** * Constant - Diamonds */ public static final int DIAMONDS = 3 ; // Card Constructor Methods /** * Creates an instance of the Card class with random values * (if all have been dealt, then starts again) */ public Card() { if (noDealt == 52) { System.err.println("all 52 cards dealt") ; initialised = false ; } if (!initialised) { for (int i = 0 ; i < 4 ; i++) for (int j = 0 ; j < 13 ; j++) dealt[i][j] = false ; initialised = true ; noDealt = 0 ; } int s, v ; do { s = (int) (Math.abs(rand.nextInt()) % 4) ; v = (int) (Math.abs(rand.nextInt()) % 13) ; } while (dealt[s][v]) ; dealt[s][v] = true ; suit = s ; value = v ; noDealt++ ; } // end of constructor method /** * Creates an instance of the Card class with specified values * (if all have been dealt, then starts again) * @param s suit of the card * @param v value of the card */ public Card(int s, int v) { if (noDealt == 52) { System.err.println("all 52 cards dealt") ; initialised = false ; } if (!initialised) { for (int i = 0 ; i < 4 ; i++) for (int j = 0 ; j < 13 ; j++) dealt[i][j] = false ; initialised = true ; noDealt = 0 ; } if ((s < 0) || (s >3)) { System.out.println("invalid suit") ; System.exit(1) ; } if ((v < 0) || (v >12)) { System.out.println("invalid value") ; System.exit(1) ; } if (dealt[s][v]) ; { System.out.println("card already used") ; System.exit(1) ; } dealt[s][v] = true ; suit = s ; value = v ; noDealt++ ; } // end of constructor method // Card Instance Methods - Selectors /** * returns the suit attribute of the card * @return the suit attribute of the card */ public int getSuit() { return suit ; } // end of method getSuit /** * returns the suit attribute of the card as a string * @return the suit attribute of the card as a string */ public String getSuitString() { switch (suit) { case SPADES : return "Spades" ; case HEARTS : return "Hearts" ; case CLUBS : return "Clubs" ; case DIAMONDS : return "Diamonds" ; default : return "Unknown" ; } } //end of method getSuitString /** * returns the value attribute of the card * @return the value attribute of the card */ public int getValue() { return value ; } // end of class getValue /** * returns the value attribute of the card as a string * @return the value attribute of the card as a string */ public String getValueString() { switch (value) { case 0 : return "Ace" ; case 1 : return "two" ; case 2 : return "three" ; case 3 : return "four" ; case 4 : return "five" ; case 5 : return "six" ; case 6 : return "seven" ; case 7 : return "eight" ; case 8 : return "nine" ; case 9 : return "ten" ; case 10 : return "Jack" ; case 11 : return "Queen" ; case 12 : return "King" ; default : return "Unknown" ; } } //end of method getValueString // Other Card Methods /** * Resets the deck of cards to all undealt */ public void restart() { for (int i = 0 ; i < 4 ; i++) for (int j = 0 ; j < 13 ; j++) dealt[i][j] = false ; noDealt = 0 ; } // end of method restart /** * return a string representing the card * @return details of the card ('value of suit') */ public String toString() { return getValueString() + " of " + getSuitString() ; } // end of method toString /* public void setSuit(int s) { // s should be in the range 0 to 3 if ((s < 0) || (s >3)) suit = 0; else suit = s; } // end of method setSuit public void setValue(int v) { // value should be in the range 0 to 12 if ((v < 0) || (v >12)) value = 0; else value = v; } // end of method setValue */ } // end of class card2、需求一代码实现如下：
package cn.bdqn.demo04;public class CardTest1 { public static void main(String[] args) { System.out.println("欢迎来到“21点”的扑克游戏！"); int num=0; int sum=0; for (int i = 1; i <= 5; i++) { Card card=new Card(); num=card.getValue()+1; System.out.println("第"+i+"张牌为:"+num); sum+=num; } System.out.println("现在的总点数为:"+sum); if(sum>21) { System.out.println("很遗憾，计算机赢，再接再厉！");} else System.out.println("恭喜你，玩家赢！"); }}3、需求二代码实现如下：
package cn.bdqn.demo04;public class CardTest2 { public static void main(String[] args) { System.out.println("欢迎来到“21点”的扑克游戏！"); int num = 0; int sum1 = 0; int sum2 = 0; // 为计算机抽牌 System.out.println("计算机抽牌："); for (int i = 1; i <= 5; i++) { Card card = new Card(); num = card.getValue() + 1; System.out.println("第" + i + "张牌为:" + num); sum1 += num; } System.out.println("计算机的总点数为:" + sum1); // 为用户抽牌 System.out.println("用户抽牌："); for (int i = 1; i <= 5; i++) { Card card = new Card(); num = card.getValue() + 1; System.out.println("第" + i + "张牌为:" + num); sum2 += num; } System.out.println("用户的总点数为:" + sum2); //判断 if(sum1<=21&&sum2>21){ System.out.println("很遗憾，计算机赢，再接再厉！"); }else if(sum1<=21&&sum2<=21){ System.out.println("很遗憾，双方都不算赢！"); }else if(sum1>21&&sum2<=21){ System.out.println("恭喜玩家赢！"); }else{ System.out.println("很遗憾，双方都超过21点！"); } }}4、需求三代码实现如下：
package cn.bdqn.demo04;import java.util.Scanner;public class CardTest3 { public static void main(String[] args) { //键盘输入 Scanner sc=new Scanner(System.in); System.out.println("欢迎来到“21点”的扑克游戏！"); int num = 0; int sum1 = 0; int sum2 = 0; // 为计算机抽牌 System.out.println("计算机抽牌："); for (int i = 1; i <= 5; i++) { Card card = new Card(); num = card.getValue() + 1; System.out.println("第" + i + "张牌为:" + num); sum1 += num; if(sum1>21){ break; } } System.out.println("计算机的总点数为:" + sum1); // 为用户抽牌 System.out.println("请您输入1(抽牌)/0(不抽牌)选择是否抽牌："); int isNum=sc.nextInt(); if(isNum==0){ System.out.println("您选择了不抽牌，游戏结束！"); }else if(isNum==1){ System.out.println("用户抽牌："); for (int i = 1; i <= 5; i++) { Card card = new Card(); num = card.getValue() + 1; System.out.println("第" + i + "张牌为:" + num); sum2 += num; } System.out.println("用户的总点数为:" + sum2); //判断 if(sum1<=21&&sum2>21){ System.out.println("很遗憾，计算机赢，再接再厉！"); }else if(sum1<=21&&sum2<=21){ System.out.println("很遗憾，双方都不算赢！"); }else if(sum1>21&&sum2<=21){ System.out.println("恭喜玩家赢！"); }else{ System.out.println("很遗憾，双方都超过21点！"); } }else{ System.out.println("选择错误，游戏结束！"); } }}5、需求四代码实现如下：
package cn.bdqn.demo04;import java.util.Scanner;public class CardTest4 { public static void main(String[] args) { // 键盘输入 Scanner sc = new Scanner(System.in); System.out.println("欢迎来到“21点”的扑克游戏！"); // 默认初始值 boolean flag = true; // 循环初始值 int zeroNum = -1; // 用户赢牌总局数 int userNums = 0; // 计算机赢牌总局数 int comNums = 0; do { int num = 0; int sum1 = 0; int sum2 = 0; // 为计算机抽牌 System.out.println("计算机抽牌："); for (int i = 1; i <= 5; i++) { Card card = new Card(); num = card.getValue() + 1; System.out.println("第" + i + "张牌为:" + num); sum1 += num; if (sum1 >21) { break; } } System.out.println("计算机的总点数为:" + sum1); // 为用户抽牌 boolean isChou = false; System.out.println("请您输入1(抽牌)/0(不抽牌)选择是否抽牌："); int isNum = sc.nextInt(); if (isNum == 0) { System.out.println("您选择了不抽牌，游戏结束！"); break; } else if (isNum == 1) { System.out.println("用户抽牌："); for (int i = 1; i <= 5; i++) { Card card = new Card(); num = card.getValue() + 1; System.out.println("第" + i + "张牌为:" + num); sum2 += num; } System.out.println("用户的总点数为:" + sum2); // 判断 if (sum1 <= 21 && sum2 >21) { userNums++; System.out.println("计算机赢，总牌局数为：" + userNums); } else if (sum1 <= 21 && sum2 <= 21) { System.out.println("很遗憾，双方都不算赢！"); } else if (sum1 >21 && sum2 <= 21) { comNums++; System.out.println("用户赢，总牌局数为：" + comNums); } else { System.out.println("很遗憾，双方都超过21点！"); } } else { System.out.println("选择错误，游戏结束！"); break; } if (flag) { System.out.println("输入0返回游戏："); zeroNum = sc.nextInt(); } else { break; } } while (zeroNum == 0); }}⛳️ 三、效果展示
1、需求一效果展示
2、需求二效果展示
3、需求三效果展示
4、需求四效果展示
码文不易，本篇文章就介绍到这里，如果想要学习更多Java系列知识，请关注博主，博主带你零基础学习Java知识。与此同时，对于日常生活有困扰的朋友，欢迎阅读我的第四栏目：《国学周更—心性养成之路》，学习技术的同时，我们也注重了心性的养成。
