Question

我目前必须制作一个播放Chuck-a-Luck游戏的程序。 Chuck a Luck是一款骰子游戏，玩家可以在三个六面骰子上下注。玩家从他们的钱包或钱包中以一定数量的欧元开始，并且可以下注任何数量的欧元，小于或等于其钱包或钱包中的当前欧元金额。下表显示了玩家可以下注的内容以及如果他们是正确的，他们将赢得什么：

玩家可以继续玩，直到他们的钱包或钱包里有钱，或者决定停止玩游戏。

Wallet theWallet = new Wallet();
double cash = 10;

JOptionPane.showMessageDialog(null,"You currently have €" + cash);

Object[] options = {"Any triple", "Big", "Field", "Small"};
int option = JOptionPane.showOptionDialog(null,"What type of bet would you like to place" , "Chuck-a-Luck", JOptionPane.YES_NO_OPTION,  JOptionPane.QUESTION_MESSAGE,null,options,null);

String input = JOptionPane.showInputDialog("How much money would you like to bet? ");
Scanner scanner = new Scanner(input);
double money = scanner.nextInt();
scanner.close();

boolean enoughMoney = theWallet.get(money);

这是我在主线上的代码，这是钱包类本身。

public class Wallet { // Wallet data type 
   // current cash in wallet 
   private double cash;  // invariant: cash >= 0.0 

   // construct wallet with zero cash 
   public Wallet() { cash = 0.0; } 

   // put an amount of money into wallet 
   // pre-condition: money > 0.0 
   public void put(double  money) { 
      assert money > 0.0 : "Wallet put method: pre-condition violated!"; 
      if (money > 0.0) cash = cash + money; 
   } 

   // get an amount of money from wallet 
   // returns true if wallet had enough cash, false otherwise 
   // pre-condition: money > 0.0 
   public boolean get(double money){ 
      assert money > 0.0 : "Wallet get method: pre-condition violated!"; 
      if (money > 0.0 && cash >= money) { 
         cash = cash - money; 
         return true; 
      } 
      return false; 
   } 

   // return current amount of cash in wallet 
   public double check() { return cash; } 

   // convert to a String data type value 
   public String toString() { 
      return getClass().getName() + "[cash = " + cash + "]"; 
   } 

} // end Wallet data type

我输入的任何有效投注都会返回布尔结果为false，而它应该为true。假设我有10英镑，我下注5英镑，它返回false，它应该返回true。有什么想法没有用？感谢

Answer 1

你必须首先在钱包里放一些钱：

Wallet theWallet = new Wallet(); 
double cash = 10;
theWallet.put(cash);

请记住，cash方法中的main变量与cash类中的Wallet类变量不同：

public class Wallet { // Wallet data type 
   // current cash in wallet 
   private double cash;  // invariant: cash >= 0.0 

   // construct wallet with zero cash 
   public Wallet() { cash = 0.0; } 

   //rest of code  
}

Answer 2

您从未将现金添加到钱包中。

Wallet theWallet = new Wallet(); double cash = 10;
theWallet.put(cash); // MISSING!

所以，你以零现金购物：）

public Wallet() { cash = 0.0; }

不确定这个类是如何工作的

2 个答案: