Question

Please help me do this program.

Add some comments on it.

*15.5 (Create an investment-value calculator) Write a program that calculates the future value of an investment at a for the calculation is given interest rate for a specified number of years. The formula investmentAmount * (1monthlyInterestRate ) years *12 futureValue Use text fields for the investment amount, number of years, and annual interest rate. Display the future amount in a text field when the user clicks the Calculate button, shown in Eigure 15.27h as Exerdise15 05 Investment Amunt 10000 Number of Years: Annual Interest Rate: 3.25 Future value: S11386.28 Calaulate (b)

Answer 1

Please find the answer below, I have mentioned all the details in the comments:

InvestmentCalc.java

//import java files

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

//class definition
public class InvestmentCalc extends JFrame{
    //Declare the required componenets
    private JLabel jlblInvestment,jlblYears,jlblRate,jlblFutureValue;
    private JTextField jtfInvestment,jtfYears,jtfRate,jtfFutureValue;
    private JButton jbtnCalculate;

    //size of the frame
    private static final int WIDTH = 500, HEIGHT = 250;

    //default constructor
    public InvestmentCalc(){
        //set the title of the frame
        setTitle("Exercise15_05");
        Container cntCalc = getContentPane();
        cntCalc.setLayout(new GridLayout(5,1));
        //create the label
        jlblInvestment = new JLabel("Investment Amount:",SwingConstants.RIGHT);
        jlblYears = new JLabel("Number of Years:",SwingConstants.RIGHT);
        jlblRate = new JLabel("Annual Interest Rate:",SwingConstants.RIGHT);
        jlblFutureValue = new JLabel("Future Value:",SwingConstants.RIGHT);


        //create the Text fields
        jtfInvestment = new JTextField();
        jtfYears = new JTextField();
        jtfRate = new JTextField();
        jtfFutureValue = new JTextField();


        //create The buttons
        jbtnCalculate = new JButton("Calculate");

        //add all components to the pane
        cntCalc.add(jlblInvestment);
        cntCalc.add(jtfInvestment);

        cntCalc.add(jlblYears);
        cntCalc.add(jtfYears);

        cntCalc.add(jlblRate);
        cntCalc.add(jtfRate);

        cntCalc.add(jlblFutureValue);
        cntCalc.add(jtfFutureValue);

        //dummy component
        cntCalc.add(new JLabel());
        cntCalc.add(jbtnCalculate);


        //Register action listener to the buttons
        jbtnCalculate.addActionListener(new CalculateListener());

        //set the dimensions and property of the window
        //set the frame's property

        setSize(WIDTH,HEIGHT);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }//end constructor
    //CalculateListener inner class

    private class CalculateListener implements ActionListener{
        //actionPerformed method
        public void actionPerformed(ActionEvent ae){
            //local variables
            double investmentAmount = Double.parseDouble(jtfInvestment.getText());
            int years = Integer.parseInt(jtfYears.getText());
            double monthlyInterestRate =
                    Double.parseDouble(jtfRate.getText()) / 1200;
            //set the value
            jtfFutureValue.setText(String.format("$%.2f",
                    (investmentAmount * Math.pow(1 + monthlyInterestRate, years * 12))));
        }
    }

    //main method
    public static void main(String args[]){
        InvestmentCalc cal = new InvestmentCalc();
    }

}

Output:

X Exercise15_05 Investment Amount: 10000 Number of Years:4 Annual Interest Rate:3.25 Future Value: $11386.28 Calculate