多条 Java 输入

Question

I am sort of a Newbie to this forum and to Java. I am having a difficult time trying to find a way to ask the user to enter more than one loan to compare from steps D down. I need to be able to ask the user for a different interest rate and number of years for the amount they entered in step A. So if they entered 10 then I would have to ask them 10 times for an interest rate and years and output it in a table format using tabs. Any help is much appreciated. Thanks in advance.

Edit: Thank you so much for your help. I updated the code.

    //A. Enter the Number Of Loans to compare
    String numberOfLoansString = JOptionPane.showInputDialog("Enter the amount of loans to compare:"); 
    //Convert numberOfLoansString to int
    int numberOfLoans = Integer.parseInt(numberOfLoansString);

    //B. Enter the Amount/Selling Price of Home
    String loanAmountString = JOptionPane.showInputDialog("Enter the loan amount:");
    //Convert loanAmountString to double
    double loanAmount = Double.parseDouble(loanAmountString);

    //C. Enter the Down Payment on the Home
    String downPaymentString = JOptionPane.showInputDialog("Enter the down payment on the Home:");
    double downPayment = Double.parseDouble(downPaymentString);


    //D. Ask the following for as many number of loans they wish to compare
    //D1 Get the interest rate
    double[] anualInterestRatesArray = new double[numberOfLoans];
    double[] monthlyInterestRateArray = new double[numberOfLoans];
    int[] numberOfYearsArray = new int[numberOfLoans];
    double[] monthlyPaymentArray = new double[numberOfLoans];
    double[] totalPaymentArray = new double[numberOfLoans];

    for (int i=0; i < numberOfLoans; i++)
    {
        String annualInterestRateString = JOptionPane.showInputDialog("Enter the interest rate:");
        double annualInterestRate = Double.parseDouble(annualInterestRateString);
        anualInterestRatesArray[i] = (annualInterestRate);

        //Obtain monthly interest rate
        double monthlyInterestRate = annualInterestRate / 1200;
        monthlyInterestRateArray[i] = (monthlyInterestRate);

        //D2 Get the number of years
        String numberOfYearsString = JOptionPane.showInputDialog("Enter the number of years:");
        int numberOfYears = Integer.parseInt(numberOfYearsString);
        numberOfYearsArray[i] = (numberOfYears);

        //Calculate monthly payment
        double monthlyPayment = loanAmount * monthlyInterestRate / (1 - 1 / Math.pow(1 + monthlyInterestRate, numberOfYears * 12));
        //Format to keep monthlyPayment two digits after the decimal point
        monthlyPayment = (int)(monthlyPayment * 100) / 100.0;
        //Store monthlyPayment values in an array
        monthlyPaymentArray[i] = (monthlyPayment);

        //Calculate total Payment
        double totalPayment = monthlyPaymentArray[i] * numberOfYears * 12;
        //Format to keep totalPayment two digits after the decimal point
        totalPayment = (int)(totalPayment * 100) / 100.0;
        totalPaymentArray[i] = (totalPayment);
    }

Answer 1

You need to do all the repeated processing logic inside a loop such as for(... ) loop. Use an array to store different values for the number of loans.

Answer 2

Use for loops for this.

PS: You can use other loops [while, do-while] as well.

Answer 3

An example for using for loop

int numberOfLoans = Integer.parseInt(numberOfLoansString); 

 //section of code which shouldnt be repeated here outside the loop.

for( int i = 0; i < numberOfLoans ; i++ )
{
      //Write Step D here  , because you want it to be repeated
}

Answer 4

You probably need to use arrays and loops. Use arrays to store all the values entered and a loop to get the values.

   double[] anualInterestRates = new double[numberOfLoans];
   double[] monthlyInterestRates = new double[numberOfLoans];
   int[] numberOfyears = new int[numberOfLoans];

Then you can loop and ask for each loan values:

   for(int i= 0; i < numberOfLoans; i++){
        //get the anual interest rate
        anualInterestRates[i] = the anual interets rate gotten
        //etc
   }

Now you have 3 arrays of values. You can use a second loop to calculate the output and display.