Simple Program for using JOptionpane Choices and Basic Calculator Java Source Code

//main class

package joptionpane;

import java.util.InputMismatchException;
import java.util.StringTokenizer;
import javax.swing.JOptionPane;

public class Main {

    public static void main(String[] args)
    {
        int ans = 0;
        boolean success = false;
       do
       {
        try
        {
            String str = JOptionPane.showInputDialog(null, "Enter numbers plus their operators", "String Calculator", JOptionPane.QUESTION_MESSAGE);

            jOptionPaneClass access = new jOptionPaneClass();

            access.getResult(str);
            if(JOptionPane.QUESTION_MESSAGE == JOptionPane.CANCEL_OPTION)
            {
                break;
            }
                
            ans = JOptionPane.showConfirmDialog(null,"Want to try again?",
                "Basic Calculator", JOptionPane.);

            success = true;
        }catch(InputMismatchException e){
             JOptionPane.showMessageDialog(null,e.getMessage(), "EXCEPTION" , JOptionPane.WARNING_MESSAGE);
         }catch(NumberFormatException e){
             JOptionPane.showMessageDialog(null,e.getMessage(), "EXCEPTION" , JOptionPane.WARNING_MESSAGE);
         }catch(ArithmeticException e){
             JOptionPane.showMessageDialog(null,e.getMessage(), "EXCEPTION" , JOptionPane.WARNING_MESSAGE);
         }catch(ArrayIndexOutOfBoundsException e){
            JOptionPane.showMessageDialog(null,e.getMessage(), "EXCEPTION" , JOptionPane.WARNING_MESSAGE);
         }catch(Exception e){
            JOptionPane.showMessageDialog(null,e.getMessage(), "EXCEPTION" , JOptionPane.WARNING_MESSAGE);

           }
       }while(ans == JOptionPane.YES_OPTION);
      
    }
}

//java Class



package joptionpane;

import java.util.StringTokenizer;
import javax.swing.JOptionPane;
public class jOptionPaneClass
{
    public void stringCalcAdd(String str)
    {
          int num1;
          int num2;


        StringTokenizer token = new StringTokenizer(str, " + ");

        while(token.hasMoreTokens())
        {


            num1 = Integer.parseInt(token.nextToken());
            num2 = Integer.parseInt(token.nextToken());
            int sum = num1+num2;
            int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

            if(ans==JOptionPane.YES_OPTION)
            {
                JOptionPane.showMessageDialog(null, "The result is: " + sum, "Result", JOptionPane.INFORMATION_MESSAGE);
            }
         }
    }

    public void stringCalcSubtract(String str)
    {

        int num1;
        int num2;


        StringTokenizer token = new StringTokenizer(str, " - ");

        while(token.hasMoreTokens())
        {


            num1 = Integer.parseInt(token.nextToken());
            num2 = Integer.parseInt(token.nextToken());
            int difference = num1-num2;
             int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

            if(ans==JOptionPane.YES_OPTION)
            {
                JOptionPane.showMessageDialog(null, "The result is: " + difference, "Result", JOptionPane.INFORMATION_MESSAGE);
            }
         }
    }

    public void stringCalcMultiply(String str)
    {

        int num1;
        int num2;


        StringTokenizer token = new StringTokenizer(str, " * ");

        while(token.hasMoreTokens())
        {


            num1 = Integer.parseInt(token.nextToken());
            num2 = Integer.parseInt(token.nextToken());
            int product = num1*num2;
             int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

            if(ans==JOptionPane.YES_OPTION)
            {
                JOptionPane.showMessageDialog(null, "The result is: " + product, "Result", JOptionPane.INFORMATION_MESSAGE);
            }
         }
    }

    public void stringCalcDivide(String str)
    {

        double num1;
        double num2;


        StringTokenizer token = new StringTokenizer(str, " / ");

        while(token.hasMoreTokens())
        {


            num1 = Integer.parseInt(token.nextToken());
            num2 = Integer.parseInt(token.nextToken());
            if(num2 > 0)
            {
            double qoutient = num1/num2;
             int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

            if(ans==JOptionPane.YES_OPTION)
            {
                JOptionPane.showMessageDialog(null, "The result is: " + qoutient, "Result", JOptionPane.INFORMATION_MESSAGE);
            }
            }
            if(num2 == 0 && num1 == 0)
            {
               String Un = "Undefined";
                int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

                if(ans==JOptionPane.YES_OPTION)
                {
                    JOptionPane.showMessageDialog(null, "The result is: " + Un, "Result", JOptionPane.INFORMATION_MESSAGE);
                }
            }
         }

    }
    public void stringCalcPower(String str)
    {
        double base;
        double power;


        StringTokenizer token = new StringTokenizer(str, " ^ ");

        while(token.hasMoreTokens())
        {


            base = Integer.parseInt(token.nextToken());
            power = Integer.parseInt(token.nextToken());
            if(power == 0)
            {
             int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

                if(ans==JOptionPane.YES_OPTION)
                {
                    JOptionPane.showMessageDialog(null, "The result is: " + 0, "Result", JOptionPane.INFORMATION_MESSAGE);
                }
            }
            else if(power == 1)
            {
               int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

                if(ans==JOptionPane.YES_OPTION)
                {
                    JOptionPane.showMessageDialog(null, "The result is: " + base, "Result", JOptionPane.INFORMATION_MESSAGE);
                }
            }
            else if(power > 1)
            {
                double pow = Math.pow(base, power);
                int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

                if(ans==JOptionPane.YES_OPTION)
                {
                    JOptionPane.showMessageDialog(null, "The result is: " + pow, "Result", JOptionPane.INFORMATION_MESSAGE);
                }
            }
            else if(power < 1)
            {
                double pow =1 / Math.pow(base, power * -1) ;
                 int ans = JOptionPane.showConfirmDialog(null,"Proceed?",
                "Basic Calculator", JOptionPane.YES_NO_CANCEL_OPTION);

                if(ans==JOptionPane.YES_OPTION)
                {
                    JOptionPane.showMessageDialog(null, "The result is: " + pow, "Result", JOptionPane.INFORMATION_MESSAGE);
                } 
            }
         }
    }
    public void getResult(String str)
    {
        for(int i=0;i<10;i++)
      {
          if(str.charAt(i) == '+')
          {
              stringCalcAdd(str);
              break;
          }
          if(str.charAt(i) == '-')
          {
              stringCalcSubtract(str);
              break;
          }
          if(str.charAt(i) == '*')
          {
              stringCalcMultiply(str);
              break;
          }
          if(str.charAt(i) == '/')
          {
              stringCalcDivide(str);
              break;
          }
          if(str.charAt(i) == '^')
          {
              stringCalcPower(str);
              break;
          }   
    }
    }
}