返回方法並在方法之間傳遞變量？

Question

我目前正在做我要編程的ATM機作業。 總共有4種方法-主，提款，存款和CHECKBALANCE。 從MAIN方法中，我有一個菜單，因此將從那里將變量發送到其余方法。

我想知道是否有辦法，如果在完成對WITHDRAWAL的總計計算之后，是否可以將該值傳遞給CHECKBALANCE？ 因為我嘗試過：

total = deposit - withdrawal;
checkbalance(withdrawal);

為了讓用戶檢查其余額，他們必須將先前選擇中計算出的值發送到CHECKBALANCE方法，對嗎？ 但是彈出的錯誤是“參數列表的長度不同”。 另外，我想知道在完成其他方法中執行的每個任務后如何返回到MAIN中的菜單。 我努力了：

choice = Integer.parseInt(JOptionPane.showInputDialog("Would you like to return to the    menu? (1 = Yes, 2 = No));

if (choice == 2)
{
System.exit(0);
}

main();

如果你們中的任何一個可以幫助我，我將非常感激。 我仍然是新手，本學期剛開始學習Java。 拜托了，謝謝大家：）

更新：

package lab2;

import javax.swing.JOptionPane;
public class LAB2 
{

    public static void main(String[] args) 
    {
        double initialAmount, withdraw = 0, deposit = 0, checkBalance = 0;
        int choice;

        initialAmount = Double.parseDouble(JOptionPane.showInputDialog("Please enter current savings amount: "));

        while(initialAmount < 0)
        {
            initialAmount = Double.parseDouble(JOptionPane.showInputDialog("Invalid amount. Amount cannot be negative. Please re-enter" ));   
        }

        choice = Integer.parseInt(JOptionPane.showInputDialog("MENU: "
                + "What would you like to do? Please choose from 1 - 4\n"
                + "1) Withdraw\n"
                + "2) Deposit\n"
                + "3) Check balance\n"
                + "4) Exit"));
        while ((choice <= 0) || (choice > 4))
        {
            choice = Integer.parseInt(JOptionPane.showInputDialog("Invalid option. Please choose between option 1 - 4: "));
        }

        if (choice == 1)
        {
            ChoiceOne(withdraw, initialAmount);
        }

        else if (choice == 2)
        {
            ChoiceTwo(deposit, initialAmount);
        }
        else if (choice == 3)
        {
            ChoiceThree(checkBalance, initialAmount);
        }

        else if (choice == 4)
        {
            System.exit(0);
        }
    }

    /////////////////////////////////////////////////////////////////////////////
    public static void ChoiceOne(double withdraw, double initialAmount)
    {
        double afterDeduction;
        int input, choice1;

        withdraw = Double.parseDouble(JOptionPane.showInputDialog("Your current balance is: RM"+initialAmount+" . How much would you like to withdraw? "));

        while (withdraw > initialAmount)
        {
            input = Integer.parseInt(JOptionPane.showInputDialog("Insufficient balance to perform withdrawal. Continue? (1 = Yes, 2 = Exit ")); 

            if (input == 2)
            {
                JOptionPane.showMessageDialog(null,"Thank you!");
                System.exit(0);
            }  
            else if (input == 1)
            {
                withdraw = Double.parseDouble(JOptionPane.showInputDialog("Your current balance is: RM"+initialAmount+" . How much would you like to withdraw? "));

                afterDeduction = initialAmount - withdraw;
                JOptionPane.showMessageDialog(null, "You have withdrawn RM"+withdraw+". Your total balanace now is: RM"+afterDeduction+".");

                choice1 = Integer.parseInt(JOptionPane.showInputDialog("Would you like to continue to menu or exit? (1 = Yes /2 = No"));

                if (choice1 == 2)
                {
                    JOptionPane.showMessageDialog(null,"Thank you!");
                    System.exit(0);
                }

                if (choice1 == 1)
                {

                }
            }
        }

        while  (withdraw < 0)
        {
            input = Integer.parseInt(JOptionPane.showInputDialog("Invalid withdrawal. Please re-enter: "));
        }

        afterDeduction = initialAmount - withdraw;
        JOptionPane.showMessageDialog(null,"You have withdrawn RM"+withdraw+". Your total balanace now is: RM"+afterDeduction+"."
                + "/nWould you like to return to the menu? ");
    }

    /////////////////////////////////////////////////////////////////////////////
    public static void ChoiceTwo (double deposit, double initialAmount)
    {
        double afterAddition; 
        int input;

        deposit = Double.parseDouble(JOptionPane.showInputDialog("How much would you like to deposit? "));

        while (deposit < 0)
        {
            input = Integer.parseInt(JOptionPane.showInputDialog("Invalid deposit. Please re-enter: "));
        }

        if (deposit > 0)
        {
        afterAddition = deposit + initialAmount;
        JOptionPane.showMessageDialog(null,"You have deposit RM"+deposit+". Your total balanace now is: RM"+afterAddition+"."
                + "/nWould you like to return to the menu? ");
        }
    }

    /////////////////////////////////////////////////////////////////////////////
    public static void ChoiceThree (double CheckBalance, double initialAmount)
    {
    }

}

Answer 1

您可以創建新對象，我們將其稱為SessionData並將所有操作數據存儲在其中。 它可以大大簡化論證傳遞問題。 根據您提供的信息，我可以提供所有這些建議。

Answer 2

我只看一小段代碼就無法完全理解您的工作，但是，如果布爾值等於true，則可以嘗試使用布爾值檢查用戶是否要返回主菜單，然后顯示如果主菜單等於false，則程序繼續執行/結束。