Java Calculator, Minus & multiplication button gets wrong answer?

Question

import java.awt.event.*;
import java.applet.Applet;
import javax.swing.*;
import java.awt.*;
public class calc extends JApplet implements ActionListener
     JTextField input = new JTextField("");
     JButton numbers[] = new JButton[10];
     JButton add = new JButton("+");
     JButton equals = new JButton("=");
     JButton minus = new JButton("-");
    JButton multiply = new JButton("*");
    JButton divide = new JButton("/");
    JButton clear = new JButton("AC");
     int num1 = 0;
     int num2 = 0;     
     String oper = " ";
     public void init()
          setLayout(null);
          setBackground(new Color(227,131,125));          
          Design();
     public void Design()
          int x = 1;
          int y= 1;
          int wi = 10;
          int he = 50;
          input.setSize(250,30);
          input.setLocation(10,10);
          add(input);
          add.setSize(80,30);
          add.setLocation(280,50);
          add.addActionListener(this);
          add(add);
          minus.setSize(80,30);
          minus.setLocation(280,90);
          minus.addActionListener(this);
          add(minus);
          multiply.setSize(80,30);
          multiply.setLocation(280,130);
          multiply.addActionListener(this);
          add(multiply);
          divide.setSize(80,30);
          divide.setLocation(280,175);
          divide.addActionListener(this);
          add(divide);
          equals.setSize(80,30);
          equals.setLocation(190,175);
          equals.addActionListener(this);
          add(equals);
         clear.setSize(80,30);
          clear.setLocation(100,175);
          clear.addActionListener(this);
          add(clear);
          while(x<=10)
               if (x==10)
               numbers[x-1] = new JButton("0");
               numbers[x-1].setSize(80,30);
               numbers[x-1].setLocation(wi,he);
               //numbers[x-1].setBackground();
               else
               numbers[x-1] = new JButton(Integer.toString(x));
               numbers[x-1].setSize(80,30);
               numbers[x-1].setLocation(wi,he);
               wi = wi + 90;
                    if(x%3==0)
                         he = he + 40;
                         wi = 10;
               numbers[x-1].addActionListener(this);
               add(numbers[x-1]);          
               x++;
     public void actionPerformed(ActionEvent act)
          int x = 0;
          while(x<10)
               if(act.getSource().equals(numbers[x]))
                    if(x==9)
                         input.setText("0");
                    else                    
                    input.setText(Integer.toString(x+1));
               x++;
          if (act.getSource().equals(add))
               num1 = Integer.parseInt(input.getText());
          else if(act.getSource().equals(equals))
               num2 = Integer.parseInt(input.getText());
               input.setText(Integer.toString(num1 + num2));
               if (act.getSource().equals(minus))
               num1 = Integer.parseInt(input.getText());
               oper = "minus";
          else if(act.getSource().equals(equals))
               num2 = Integer.parseInt(input.getText());
               if(oper.equals("minus"))
                    input.setText(Integer.toString(num1 - num2));
               if (act.getSource().equals(multiply))
               num1 = Integer.parseInt(input.getText());
               oper = "multiply";
          else if(act.getSource().equals(equals))
               num2 = Integer.parseInt(input.getText());
               if(oper.equals("multiply"))
                    input.setText(Integer.toString(num1 * num2));
The addition button is working, but i cant seem to make minus and multiply button work, they get wrong answer when i use them.. what could bee the problem with my code

Answer 1

Sorry, but I don't see a simple fix in this code here (Hopefully I'm wrong and someone else will see this, but I don't) Because of this, I recommend that you fully scrap this code and start over from square one. I don't think that you really "see" your logic here. To help you see what you are trying to do, you need to separate your logic from your GUI. Try to build a non-gui calculator that works via simple console menu. Once you get this working, then use this code to create a GUI calculator.