Question

I am trying to create an applet for class.

I am supposed to handle two possible user input mistakes. I have handled the division by zero with an if/else statement.

However. I am trying to handle an exception if the user tries to put letters or symbols into the text boxes instead of numbers….but my catch statement will not catch the issue. instead it enacts the division by 0 else statement. Please have a look and let me know if you can help

 /*
 * Curtis Sizemore
 * IT 259 - Intermediate Java
 * Unit 8
 * Working with Applets
 * I attest that this is a product of my own creation.
 * 
 */
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JTextField;

/**
 *
 * @author Curtis
 */
public class JDivide extends JApplet implements ActionListener
{
JTextField numer = new JTextField(5);
JTextField denom = new JTextField(5);
JLabel intro = new JLabel("Please enter two numbers.");
JLabel num = new JLabel("Numerator: ");
JLabel den = new JLabel("Denominator: ");
JLabel result = new JLabel();
JButton solve = new JButton("Click Me to Solve!");
Container con = getContentPane();
double numerator;
double denominator;
 double quotient;
 String n;
String d;
 String q;


@Override
public void init()
{
    con.setLayout(new FlowLayout());
    con.add(intro);
    con.add(num);
    con.add(numer);
    con.add(den);
    con.add(denom);
    con.add(solve);
    con.add(result);
    solve.addActionListener(this);
}

@Override
public void actionPerformed(ActionEvent e) 
{



      n = numer.getText();
      d = denom.getText();
    try
      {
      double numerator = Double.parseDouble(n);
    double denominator = Double.parseDouble(d);
      }
      catch(NumberFormatException x)
      {
      result.setText("Numbers Only Please.");
      }


      if(denominator==0)
      {
      result.setText("Division by 0 is undefined.");
      }
      else
      {
      double quotient = numerator/denominator;
      q = Double.toString(quotient);
      result.setText(q);
}
 }

}

Answer 1

You need to put the rest of your code inside of the try block, either that or throw an exception. Else the method will still try to calculate the quotient even if non-numbers are entered.