Hi guys, Im pretty new to Java so bare with me as I make a complete fool of myself. Im trying to start out by making a simple calculator, capable of the functions plus, minus, divide, multiply. I had no trouble doing this within eclipse, however turning it into a windowed program made it a lot harder for me.

The basic problem im having is using the method:

String = JOptionPane.showInputDialog("text")

Mine looks like this:

Code:

inStr1 = JOptionPane.showInputDialog("Please Input an Equation\n" +
"* = multiply, / = Divide,\n" +
"Include spaces and Decimals (Using Doubles!)\n" +
"For example: 2.0 + 4.2, Then ENTER!");

This works all fine and dandy however I can no longer perform math with this, as it is a string. I know how to use the Double.parseDoube(), however I need it to break a line like "2.0 + 4.2" into Double num1 = 2.0; String sign = +; Double num2 = 4.2;

A good chunk of the problematic area, As you can see I tried playing around with a few things but I am completely lost at this point lol, thanks in advance.

Code:

import java.util.*;
import javax.swing.*;
import java.io.*;
import java.util.regex.*;
public class Calculator {
static Scanner console = new Scanner(System.in);
public static void main(String[] args)
{
// System.out.println("Please Input an Equation\n" +
// "* = multiply, / = Divide,\n" + <--- Non-Windowed
// "Include spaces and Decimals (Using Doubles!)\n" +
// "For example: 2.0 + 4.2, Then ENTER!");
double num1;
double num2;
double sum;
String sign;
String num1a;
String num2a;
String inStr1;
String inStr2;
String outStr;
int repeats;
num1a = "a";
num2a = "b";
sum = 1;
inStr1 = JOptionPane.showInputDialog("Please Input an Equation\n" +
"* = multiply, / = Divide,\n" +
"Include spaces and Decimals (Using Doubles!)\n" +
"For example: 2.0 + 4.2, Then ENTER!");
String data = inStr1;
String[] values = data.split(" ");
num1a = String[0];
sign = String[1];
num2a = String[2];
num1 = Double.parseDouble(num1a);
num2 = Double.parseDouble(num2a);
// num1 = console.nextDouble(); <--- Old code (The none window
// sign = console.next(); way)
// num2 = console.nextDouble();
if (sign.equals("+")){
sum = num1 + num2;
}
if (sign.equals("-")){
sum = num1 - num2;
}
if (sign.equals("*")){
sum = num1 * num2;
}
if (sign.equals("/")){
sum = num1 / num2;
}

I believe the part here: String[] values = data.split(" "); is the proper way of doing it, however I don't think the String[0] part is right.