I know alot of you guys get the same posts over and over about intro JavaII Classes, but I have tried to refrain from asking something that has already been solved and try learning on my own, but Im stumped.

Im having trouble with this program, specifically at my calculation button. I cannot get my calculations to function. I hope the issue is minute and can be easily pointed out. Any and all help is needed/wanted, and if you have time, maybe a brief snyopsis of what I'm doing wrong so that I can fix my logic for future coding

below is a Mortgage Calculator, GUI that relys on user inputted values for the Terms, interest rate, mortgaged amount.

import java.text.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;


public class Calculator extends javax.swing.JFrame {

    /**
     * Creates new form Calculator
     */
    public Calculator() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        calcButt = new javax.swing.JButton();
        quitButt = new javax.swing.JButton();
        loanTermF = new javax.swing.JTextField();
        intRateF = new javax.swing.JTextField();
        loanAmtF = new javax.swing.JTextField();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        jLabel3 = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        jScrollPane1 = new javax.swing.JScrollPane();
        outputF = new javax.swing.JTextArea();
        clearButt = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        calcButt.setText("Calculate");
        calcButt.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                calcButtActionPerformed(evt);
            }
        });

        quitButt.setText("QUIT");
        quitButt.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                quitButtActionPerformed(evt);
            }
        });

        intRateF.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                intRateFActionPerformed(evt);
            }
        });

        loanAmtF.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                loanAmtFActionPerformed(evt);
            }
        });

        jLabel1.setText("Loan Amount");

        jLabel2.setText("Interest Rate");

        jLabel3.setText("Loan Terms");

        jLabel4.setText("Mortgage Calculator");

        outputF.setColumns(20);
        outputF.setRows(5);
        jScrollPane1.setViewportView(outputF);

        clearButt.setText("Clear");
        clearButt.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                clearButtActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(93, 93, 93)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jScrollPane1)
                    .addGroup(layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
                                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                                    .addComponent(jLabel2, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                                    .addComponent(jLabel1)
                                    .addComponent(jLabel3, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                                .addGap(95, 95, 95))
                            .addGroup(layout.createSequentialGroup()
                                .addComponent(calcButt)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 16, Short.MAX_VALUE)
                                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                                        .addComponent(jLabel4)
                                        .addGap(18, 18, 18))
                                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                                        .addComponent(clearButt)
                                        .addGap(35, 35, 35)))))
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                            .addComponent(quitButt, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(loanTermF)
                            .addComponent(intRateF)
                            .addComponent(loanAmtF))))
                .addGap(152, 152, 152))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel4, javax.swing.GroupLayout.DEFAULT_SIZE, 40, Short.MAX_VALUE)
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(loanAmtF, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel1))
                .addGap(36, 36, 36)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(intRateF, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel2))
                .addGap(38, 38, 38)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(loanTermF, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel3))
                .addGap(41, 41, 41)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(quitButt)
                    .addComponent(calcButt)
                    .addComponent(clearButt))
                .addGap(18, 18, 18)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(127, 127, 127))
        );

        pack();
    }// </editor-fold>

    private void calcButtActionPerformed(java.awt.event.ActionEvent evt) {
//Calculate the monthly payment of the mortgage
//payment = (PV * Rate) / (1 - Math.pow(1 + Rate, - Year));

   
        
        double loanAmount = lAmt;
        double loanInterest = lInt;
        double loanTerm = lTerm;
        double monthlyPayment = mPayment
                
                double lAmt = 0;
                double lInt = 0;
                double lTerm = 0;
                double mPayment = 0;
                        
                
        
        mPayment = Double.parseDouble (intRateF.getText());
        lAmt = Double.parseDouble (loanAmtF.getText());
        lInt = Double.parseDouble (intRateF.getText());
        lTerm = Double.parseDouble (loanTermF.getText());
        
        mPayment = ((lAmt * lInt) / (1 - Math.pow(1 + lInt - lTerm)));
        
        outputF.setText(string.valueOf(mPayment));
        
        
        
    }

    private void quitButtActionPerformed(java.awt.event.ActionEvent evt) {
       System.exit(0);
    }

    private void clearButtActionPerformed(java.awt.event.ActionEvent evt) {
        loanAmtF.setText(null);
        intRateF.setText(null);
        loanTermF.setText(null);
    }

    private void loanAmtFActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:
    }

    private void intRateFActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /*
         * Set the Nimbus look and feel
         */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /*
         * If Nimbus (introduced in Java SE 6) is not available, stay with the
         * default look and feel. For details see
         * http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Calculator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Calculator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Calculator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Calculator.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /*
         * Create and display the form
         */
        java.awt.EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Calculator().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify
    private javax.swing.JButton calcButt;
    private javax.swing.JButton clearButt;
    private javax.swing.JTextField intRateF;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextField loanAmtF;
    private javax.swing.JTextField loanTermF;
    private javax.swing.JTextArea outputF;
    private javax.swing.JButton quitButt;
    // End of variables declaration
}

@ line 161 you forgot the semicolon [TEX](;)[/TEX]

then declare the variables at line 163-166 before using them like in line 158-161

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.