Question

我是新来的Java请帮帮我，我的局部变量不能带我方法参数。

        import javax.swing.*;
        import java.util.*;
        import java.io.*;
        import java.text.DecimalFormat; //I can not get my local variables in my
                                             // main to accept my methods parameters.


       // This is my program.
         public class AccountBank
         {
        public static void main (String[] args) throws IOException
         {  
            // Calling in my Class
            Accountclass BankAcc = new Accountclass();

            // initialize both there variables in. order to use them in a for loop.
            double depDrw = 0;// this are one of the variables that is giving me problems
            double withDrw = 0; // this is the other that is giving me problems
            double totalW = 0;
            double totalD = 0;

            // declaring all my variables
            String name="";
            double month;
            double startBal;


// This section will greet and accept input by asking the user to enter the starting alance and set it in my class


            // Greetings
            JOptionPane.showMessageDialog(null,"Lets Get Started");

            // receiving input for my name variable
        name = JOptionPane.showInputDialog(null, "Please Enter Your Name Below: ");

            // ask user for starting balance
            startBal = Double.parseDouble(JOptionPane.showInputDialog("What Is The Starting Balance In Your Account:"));
            // This will set the value in my class  
            BankAcc.setBal(startBal); 

            // ask user how many months has the account been active
            month = Double.parseDouble(JOptionPane.showInputDialog("Months That Account Has Been Active:"));




            // This section will accept input by asking the user to enter each amount deposited every month from the account set it in my class.


                // This will be shown in the message box
                depDrw = depositTotal(deposit); << // I am having trouble here it wont take my parameters variable which I created on the buttom.  please help
                // This will sum up every amount the user enters in the message box.
                totalD += depDrw; 

                // This will set the value in my class
                BankAcc.setdeposit(totalD);

//此部分将接受输入，要求用户输入每月从帐户中提取的每笔金额并在我的课程中设置

                // This will be shown in the message box
                withDrw = withdrawTotal(wit); // <<< I am having problem here this variable does not take the value of my methods parameter, which i created on the bottom of this page.
                // This will sum up every amount the user enters in the message box.
                totalW += withDrw;
                // This will set the value in my class
                BankAcc.setwithdraws(totalW);




//This section will display the " monthly interest rate, monthly interest earned, total amount deposited, total amount withdrawn, and the final balance of the account." 

                DecimalFormat formatter = new DecimalFormat("#0.0000");
                DecimalFormat formatter2 = new DecimalFormat("#0.0");
                DecimalFormat formatter3 = new DecimalFormat("#0.00");

            //Get the calculations from the savings account class and display them.
                JOptionPane.showMessageDialog(null," Account Name:  " +name+"\n \n Your Monthly Interest Rate Is .....  " 
                + formatter.format(BankAcc.monthInt())+"%" + "\n \n Your Monthly Interest Earned Was .....  $"
                + formatter2.format(BankAcc.GetInt()) + "\n \n Your Overall Amount With Deposited Was .....  $" + totalD +
                " \n \n Your Overall Amount WithDrawn Was .....  $" + totalW  + " \n \n Your Remaining Balance Is .....  $"
                + formatter3.format(BankAcc.getFinalbal()),"Results", JOptionPane.PLAIN_MESSAGE );



    }

    public static double depositTotal( String deposit)
                                throws IOException
        {
            double sales;
            double totalDeposit = 0;

            File file = new File ("deposits.txt");
            Scanner inputfile = new Scanner(file);

            while (inputfile.hasNextDouble());
            {
                sales = inputfile.nextDouble();
                totalDeposit += sales;
            }

            inputfile.close();

            return totalDeposit;

        }

    public static double withdrawTotal( String wit)
                                throws IOException
        {
            double sales;
            double totalwithdraws = 0;

            File file = new File ("withdraws.txt");
            Scanner inputfile = new Scanner(file);

            while (inputfile.hasNextDouble());
            {
                sales = inputfile.nextDouble();
                totalwithdraws += sales;
            }

            inputfile.close();

            return totalwithdraws;

        }

Answer 1

更改方法声明，使其不接收任何参数。因为它返回一个double，你可以将它返回的值存储在double变量中：

double deposit = depositTotal();

在depositTotal()方法中：

public static double depositTotal() throws IOException {
... 
}

Answer 2

你的while循环是

while (inputfile.hasNextDouble());
        {
            sales = inputfile.nextDouble();
            totalDeposit += sales;
        }

在;

之后不应该有(inputfile.hasNextDouble())

while (inputfile.hasNextDouble())
            {
                sales = inputfile.nextDouble();
                totalDeposit += sales;
            }

对于其他while循环，请删除;

局部变量不能取方法参数

2 个答案: