create a simple calculator uwith visual basic

Steps

1. 1
   Open Visual Basic 6.0 and create a new Standard EXE Project. Standard EXE projects give you a handful of commands and tools, useful to develop simple as well as semi-complex programs.

   • You can also choose a VB Enterprise Edition Project which will give you a lot more tools to work with. For a beginner programmer, it is suggested to use a Standard EXE Project.
2. 
   2
   Understand the project screen. In the center of the screen will be a box with a lot of dots. This is your form. A form is the place where you will add the various elements (command buttons, pictures, text boxes, etc) to your program.

   • To the left of the screen is the toolbox. The Toolbox contains various pre-defined elements of any program. You can drag and drop these elements onto your form.
   • To the lower right of the screen is the form layout. This determines where your program will be displayed on the screen once the project is complete and executed.
   • On the mid-right is the properties box which determine the property of any element that is selected in a form. You can change various properties using this. If no element is selected, it displays the properties of the form.
   • On the top-right is the project explorer. It shows the various designs, forms that are included in a project.
   • If any of these boxes is missing, you can add them by clicking on the "View" button on the Menu bar.
3. 
   3
   Drag a label onto the form, and change the caption of the label to "Enter first number".

   • The caption of a label can be changed using the properties box.
4. 
   4
   Create a textbox to the right of the first label. Remove any text that appears inside the textbox by changing blanking the "Text" field in properties box.
5. 
   5
   Create another label and change the caption to "Enter second number" and create another textbox to its right.
6. 
   6
   Drag and create four command buttons below these two labels. Change the caption of these command buttons to "Add", "Subtract", "Multiply", "Divide" respectively.
7. 
   7
   Create another label with a caption "Result" and a textbox to the right of it below the four command buttons. This textbox will be used to display the result. With this, your design is complete.
8. 
   8
   To start coding, in the project explorer, click on the form and then select the left-most button. It will take you to the coding screen.

   • Click on the list box in the top-left of the coding screen. One by one, click on all the commands (Command1, Command2, etc) so that the outline coding of them will be visible to you on your coding screen.
9. 
   9
   Declare the variables. To declare:

   • Dim a, b, r as Integer
   • a is the value entered in the first textbox, b is the value entered in the second textbox and r is the result. You can any other variables too.
10. 
    10
    Start the coding for the add command (Command1). The code will be as follows:

    • Private Sub Command1_Click()
      a = Val(Text1.Text)
      b = Val(Text2.Text)
      r = a + b
      Text3.Text = r
      End Sub
11. 
    11
    Code for the subtract command (Command2). The code will be as follows:

    • Private Sub Command2_Click()
      a = Val(Text1.Text)
      b = Val(Text2.Text)
      r = a - b
      Text3.Text = r
      End Sub
12. 
    12
    Code for the multiply command (Command3). The code will be as follows:

    • Private Sub Command3_Click()
      a = Val(Text1.Text)
      b = Val(Text2.Text)
      r = a * b
      Text3.Text = r
      End Sub
13. 
    13
    Code for the divide command (Command4). The coding will be as follows:

    • Private Sub Command4_Click()
      a = Val(Text1.Text)
      b = Val(Text2.Text)
      r = a / b
      Text3.Text = r
      End Sub
14. 
    14
    Click the start button or press F5 to execute your program.

    • Test all the commands and see if your program is working.
15. 
    15
    Save your project and your form. Make your project and save it as a .exe file on your computer; run it whenever you want!

Tips

• Add colours to the form and the text boxes, using the properties box to make it appear colourful!
• If there is an error, learn to debug the program.
• You can create different variations of a simple calculator. Try using the option box instead of command buttons.