无法更新双倍（余额）

Posted 2023-02-22

【中文标题】无法更新双倍（余额）

【英文标题】：Cannot get double(balance) to update

【发布时间】：2017-04-24 08:38:36

【问题描述】：

“我正在尝试制作一个银行应用程序，每次您输入存款或取款时都会更新余额。我的菜单和其他一切都运行良好，但在打印出最终余额时，余额始终保持在 5000.00。我哪里做错了？”

            double balance = 5000.00;

                    switch(menu)

                            case 'd': case 'D':
                                double deposit = depositFunds(balance); 
                                break;

                            case 'w': case 'W':
                                double withdrawl = withdrawFunds(balance);
                                break;

                            case 'b': case 'B':
                                checkBalance(accountNumber, balance);
                                break;

                    //end of switch     

    //end of main

     public static double depositFunds(double balance)

        Scanner input = new Scanner(System.in);

        System.out.print("\nEnter the amount of the deposit: ");

        double deposit = input.nextInt();

        double currentBalance = (balance + deposit);

        return currentBalance;

     //end of depositFunds

     public static double withdrawFunds (double balance)

            Scanner input = new Scanner(System.in);

            double currentBalance;

            System.out.print("\nEnter the amount of the withdrawal: ");

            double withdrawal = input.nextInt();

            currentBalance = (balance - withdrawal);

            return currentBalance;

     //end of withdrawFunds

     //Display the balance
     public static void checkBalance(int accountNumber, double balance)

            System.out.printf("\nAccount Number: %d has a current balance of: %.2f\n" , accountNumber , balance);

     //end of checkBalance

【问题讨论】：

您需要将计算值分配给“余额”。你没有改变它

我要提取负数;)

将计算值分配给“余额”是什么意思？我在哪里做呢？

【参考方案1】：

改为这样做：

switch(menu)

                        case 'd': case 'D':
                            balance = depositFunds(balance); 
                            break;

                        case 'w': case 'W':
                            balance = withdrawFunds(balance);
                            break;

                        case 'b': case 'B':
                            checkBalance(accountNumber, balance);
                            break;

             

【讨论】：

哦，好吧！不敢相信我错过了...谢谢！