Java Error Question

[GamerMax5]

I wrote a crappy little calculator application for practice. When I go to compile the code, I get this exception returned:

Incompatible types:
Found: void
required java.lang.String

And then it points to a random place in the line of code that it says has an error. Here is the code:

import javax.swing.*;

public class JavaCalculator
{
	public static void main(String[] args)
	{
		//declare variables
		String choice;
		String inputOperation;
		String inputNumber1;
		String inputNumber2;
		String finalOutput;
		int number1;
		int number2;
		
		//get the operation from the user
		inputOperation = JOptionPane.showInputDialog(null, "Enter the type of operation you would like to perform.\n\n" + "Enter 'add', 'sub', 'mul', or 'div'. The field is not case sensitive.", "Java Calculator",  JOptionPane.PLAIN_MESSAGE);
		
		//check for operation type
		//perform operations accordingly
		if (inputOperation.equalsIgnoreCase("add"))
		{
			//addition block
			//get the numbers from the user
			inputNumber1 = JOptionPane.showInputDialog(null, "Enter the first number: ", "Java Calculator", JOptionPane.PLAIN_MESSAGE);
			inputNumber2 = JOptionPane.showInputDialog(null, "Enter the second number: ", "Java Calculator", JOptionPane.PLAIN_MESSAGE);
			
			//convert the numbers so that they are useable
			number1 = Integer.parseInt(inputNumber1);
			number2 = Integer.parseInt(inputNumber2);
			
			//output the final result
			finalOutput = JOptionPane.showMessageDialog(null, "Your equation is: " + number1 + " + " + number2 + "\n" + "Your answer is: " + (number1 + number2), "Java Calculator", JOptionPane.PLAIN_MESSAGE);
		}
		else if (inputOperation.equalsIgnoreCase("sub"))
		{
			//subtraction block
			//get the numbers from the user
			inputNumber1 = JOptionPane.showInputDialog(null, "Enter the first number: ", "Java Calculator", JOptionPane.PLAIN_MESSAGE);
			inputNumber2 = JOptionPane.showInputDialog(null, "Enter the second number: ", "Java Calculator", JOptionPane.PLAIN_MESSAGE);
			
			//convert the numbers so that they are useable
			number1 = Integer.parseInt(inputNumber1);
			number2 = Integer.parseInt(inputNumber2);
			
			//output the final result
			finalOutput = JOptionPane.showMessageDialog(null, "Your equation is " + number1 + " - " + number2 + "\n" + "Your answer is: " + (number1 - number2), "Java Calculator", JOptionPane.PLAIN_MESSAGE);
		}
		else if (inputOperation.equalsIgnoreCase("mul"))
		{
			//multiplication block
			//get the numbers from the user
			inputNumber1 = JOptionPane.showInputDialog(null, "Enter the first number: ", "Java Calculator", JOptionPane.PLAIN_MESSAGE);
			inputNumber2 = JOptionPane.showInputDialog(null, "Enter the second number: ", "Java Calculator", JOptionPane.PLAIN_MESSAGE);
			
			//convert the numbers so that they are useable
			number1 = Integer.parseInt(inputNumber1);
			number2 = Integer.parseInt(inputNumber2);
			
			//output the final result
			finalOutput = JOptionPane.showMessageDialog(null, "Your equation is " + number1 + " * " + number2 + "\n" + "Your answer is " + (number1 * number2), "Java Calculator", JOptionPane.PLAIN_MESSAGE);
		}
		else if (inputOperation.equalsIgnoreCase("div"))
		{
			//division block
			//get the numbers from the user
			inputNumber1 = JOptionPane.showInputDialog(null, "Enter the first number: ", "Java Calculator",  JOptionPane.PLAIN_MESSAGE);
			inputNumber2 = JOptionPane.showInputDialog(null, "Enter the second number: ", "Java Calculator",  JOptionPane.PLAIN_MESSAGE);
			
			//conver the numbers so that they are useable
			number1 = Integer.parseInt(inputNumber1);
			number2 = Integer.parseInt(inputNumber2);
			
			//output the final result
			finalOutput = JOptionPane.showMessageDialog(null, "Your equation is " + number1 + " / " + number2 + "\n" + "Your answer is " + (number1 / number2), "Java Calculator", JOptionPane.PLAIN_MESSAGE);
		}
		System.exit(0);
	}
}

The exception is usually thrown around the message output for the answer. What is wrong here? I don't see anything.

[oceanebelle]

finalOutput = JOptionPane.showMessageDialog(null, "Your equation is " + number1 + " / " + number2 + "\n" + "Your answer is " +(number1 / number2), "Java Calculator", JOptionPane.PLAIN_MESSAGE);

take out finalOutput since showMessageDIalog returns void.

[oceanebelle]

and this applies to all 4 output

[GamerMax5]

I didn't know that returned a void. Thx.