My task is to code an applet that should take 2 fractions and either add,

subtract, multiply, or divide them (depending on which JButton the user

uses). Then, the fraction is to be converted to lowest terms. Also the

fractions will be entered in in terms of 2/5 for "two-fifths".

All of the calculations should be computed using basic methods. As you can

see, I have some of them already in there.

I have most of the code done but I can't seem to get past this runtime

error. This code will compile, but once I hit any one of the JButtons I

get the same runtime error.

Go ahead and compile it, and run the applet to see what I am talking

about.

Also if you guys want to push me any insight on the multiply and divide

methods, I would appreciate it.

The spacing got screwey when i cut/pasted it here, so please bear with me.

```
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
public class Fractions extends JApplet implements ActionListener
{
JLabel firstFraction, secondFraction, answerLabel; // Declares Labels
JTextField firstField, secondField, answerResults; // Declares Fields
JButton add, mult, sub, div; // Declares Buttons
public void init () // Start GUI setup
{
setSize(350, 200);
Container c = getContentPane();
c.setLayout(new FlowLayout () );
firstFraction = new JLabel( "Fraction 1 ");
c.add(firstFraction);
firstField = new JTextField(25);
c.add (firstField);
secondFraction = new JLabel( "Fraction 2 ");
c.add(secondFraction);
secondField = new JTextField(25);
c.add (secondField);
add = new JButton("+");
add.addActionListener(this);
c.add(add);
sub = new JButton("-");
sub.addActionListener(this);
c.add(sub);
mult = new JButton("*");
mult.addActionListener(this);
c.add(mult);
div = new JButton("/");
div.addActionListener(this);
c.add(div);
answerResults = new JTextField(20);
answerResults.setEditable(false);
c.add(answerResults);
} // End GUI setup
public void actionPerformed(ActionEvent e)
{
int numerator1 = ( getNumerator ( firstFraction.getText () ) ); // Gets Numerator of first fraction entered by user.
int denomerator1 = ( getDenominator ( firstFraction.getText () ) ); // Gets Denomerator of first fraction entered by user.
int numerator2 = ( getNumerator ( secondFraction.getText () ) ); // Gets Numerator of second fraction entered by user.
int denomerator2 = ( getDenominator ( secondFraction.getText () ) ); // Gets Denomerator of second fraction entered by user.
if ( e.getSource() == add )
{
addFractions(numerator1, numerator2, denomerator1, denomerator2);
}
else if ( e.getSource () == sub )
{
subtractFractions(numerator1, numerator2, denomerator1, denomerator2);
}
}
public void subtractFractions(int numerator1, int numerator2, int denomerator1, int denomerator2)
{
int numeratorsubtract = ( numerator1 * denomerator2 +( numerator2 * (-1))* denomerator1 );
int denomeratorsubtract = ( denomerator1 * denomerator2);
answerResults.setText ("" + numeratorsubtract +"/" + denomeratorsubtract );
}
public void addFractions(int numerator1, int numerator2, int denomerator1, int denomerator2)
{
int numeratoradd = ( numerator1 * denomerator2 + numerator2 * denomerator1 );
int denomeratoradd = (denomerator1 * denomerator2);
answerResults.setText ("" + numeratoradd +"/" + denomeratoradd);
}
public int getNumerator(String fraction)
{
int numerator = fraction.indexOf("/");
return ( Integer.parseInt ( fraction.substring( 0, numerator ) ) );
}
public int getDenominator(String fraction)
{
int denominator = fraction.indexOf("/");
return ( Integer.parseInt ( fraction.substring( denominator + 1, fraction.length() ) ) );
}
}
```

*Edited 3 Years Ago by happygeek*: fixed formatting