27042 total geeks with 3527 solutions
Recent challengers:
 Welcome, you are an anonymous user! [register] [login] Get a yourname@osix.net email address 

Articles

GEEK

User's box
Username:
Password:

Forgot password?
New account

Shoutbox
MaxMouse
It's Friday... That's good enough for me!
CodeX
non stop lolz here but thats soon to end thanks to uni, surely the rest of the world is going good?
stabat
how things are going guys? Here... boring...
CodeX
I must be going wrong on the password lengths then, as long as it was done on ECB
MaxMouse
lol... the key is in hex (MD5: of the string "doit" without the "'s) and is in lower case. Maybe i should have submitted this as a challenge!

Donate
Donate and help us fund new challenges
Donate!
Due Date: Sep 30
September Goal: $40.00
Gross: $0.00
Net Balance: $0.00
Left to go: $40.00
Contributors


News Feeds
The Register
Alleged mobile
spyware sellers
cuffed in US
Grooveshark caught
in a net of its own
making
FBI opens Malware
Investigator portal
to industry
TEENS ON THE
RAMPAGE: Kids in
iPhone 6 "Will it
bend" YouTube
"prank"
OpenDaylight floats
2.0 "Helium"
release
Mine Bitcoins with
PENCIL and PAPER
Canberra drone team
dances a samba in
Outback Challenge
Opposition: we
passed Australia"s
"spook"s charter"
on PURPOSE
Alca-Lu spinoff
Nuage plugs into
Oracle SDN
What"s a Chromebook
good for? How about
running PHOTOSHOP?
Slashdot
FBI Plans To Open
Up Malware Analysis
Tool To Outside
Researchers
LTE Upgrade Will
Let Phones Connect
To Nearby Devices
Without Towers
CloudFlare
Announces Free SSL
Support For All
Customers
Energy Utilities
Trying To Stifle
Growth of Solar
Power
Tor Executive
Director Hints At
Firefox Integration
CEO of Spyware
Maker Arrested For
Enabling Stalkers
Man Walks Past
Security Screening
Staring At iPad
Causing Airport
Evacuation
New Research Casts
Doubt On the
"10,000 Hour Rule"
of Expertise
Microsoft Revives
Its Hardware
Conference
Former GM Product
Czar: Tesla a
"Fringe Brand"
Article viewer

A Simple Calculator in Visual Basic for Beginners



Written by:sowoolumide
Published by:SAJChurchey
Published on:2010-03-22 22:37:02
Topic:Visual Basic
Search OSI about Visual Basic.More articles by sowoolumide.
 viewed 37012 times send this article printer friendly

Digg this!
    Rate this article :
This is a more optimized Visual Basic calculator. It contains neater code and lets you understand better on how you can code the same calculator. In short, neater code.

Requirements:

Visual Studio/ Visual basic express.
Understanding of the visual studio or visual basic environment.

1.Launch Visual Studio/ Visual Basic
2. Create a new project and name it whatever you want, e.g Calculator.
............................................................................................



Leave the form in the default name, which should be "form1" or rename it if you want in the properties pane.

Now drag buttons on the form to make it look like the diagram below.
The buttons can be resized to look how you want them to look. The text box was also resized.
For the text on the buttons, click the button you want to change its text value and go to the properties pane, you would see the text property there. you can change it there.



Now use the following names for the buttons on the forms.

BUTTONS
"1" - Button1
"2" - Button2
"3" - Button3
"4" - Button4
"5" - Button5
"6" - Button6
"7" - Button7
*"8" - Button8
*"9" - Button9
*"0" - Button10
*"+" - Button_Add
"" - Button_Multiply
*"-" - Button_Minus
*"=" - Button_Equal
*"C" - Button_Clear
*"/" - Button_Divide
*"." - Button_Point
Text box - Textbox1.text



Double click on the form and add the following code.

Public Class Form1
    ' We create this variables as globals so they can be accessed from any where in the program.

    ' this varible is for the mathematical symbol clicked. e.g +, - .
    Dim sign As Char
    ' This variable stores the first value entered by the user.
    Dim first As Double
    ' This variable stores the second value entered by the user.
    Dim second As Double
    ' This variable stores the answer of the calculation
    Dim ans As Double
    ' This variable stores a value 1 or 0 to tell if the calculation is complete or not.
    Dim stat As Integer

    '
    Sub confirm()
        stat = 1
        first = TextBox1.Text
    End Sub
    ' This subroutine checks the mathematical symbol that was clicked using a select case statement.
    ' This is more efficient then using several if statements.
    ' Then its performs the calculation based on the symbol chosen.
    ' It then sets the calculator status to 1 to show the calculation is complete(stat=1).
    ' It then displays your result in the textbox (TextBox1.Text = ans)
    Sub action()

        Select Case sign
            Case "+"
                ans = first + TextBox1.Text
            Case "-"
                ans = first - TextBox1.Text
            Case "*"
                ans = first * TextBox1.Text
            Case "/"
                ans = first / TextBox1.Text

            Case Else

        End Select
        stat = 1
        TextBox1.Text = ans
    End Sub

    Sub addnum(ByRef a As String)

        If TextBox1.Text = 0 Then
            TextBox1.Text = a
        Else
            TextBox1.Text = TextBox1.Text & a
        End If
        If stat = 1 Then
            TextBox1.Text = a
            stat = 0
        End If
    End Sub

    ' using addnum() in the button click event prevents having to write the same code for every button click.
    ' event. The parameter in the subroutine is the number that should be added to the text button on the button click.
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        addnum(1)
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        addnum(2)
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        addnum(3)
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        addnum(4)
    End Sub

    Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
        addnum(5)
    End Sub

    Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
        addnum(6)
    End Sub

    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
        addnum(7)
    End Sub

    Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button8.Click
        addnum(8)
    End Sub

    Private Sub Button9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button9.Click
        addnum(9)
    End Sub

    Private Sub Button10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button10.Click
        addnum(0)
    End Sub

    Private Sub Button_Add_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Add.Click
        sign = "+"
        confirm()
    End Sub

    Private Sub Button_Minus_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Minus.Click
        sign = "-"
        confirm()
    End Sub

    Private Sub Button_Multiply_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Multiply.Click
        sign = "*"
     confirm()
    End Sub

    Private Sub Button_Divide_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Divide.Click
        sign = "/"
       confirm()
    End Sub

    Private Sub Button1_Clear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1_Clear.Click
        TextBox1.Text = 0
        stat = 0
        first = TextBox1.Text
    End Sub

    Private Sub Button_Equal_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Equal.Click
        action()

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button_Point_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Point.Click
        addnum(".")
    End Sub
End Class

Did you like this article? There are hundreds more.

Comments:
Anonymous
2010-12-07 06:52:48
how about in if else statement only???
pointblank
2011-04-20 18:59:18
thx for the code. http://www.dudijaya.com
Anonymous
2011-06-30 11:00:38
good
Anonymously add a comment: (or register here)
(registration is really fast and we send you no spam)
BB Code is enabled.
Captcha Number:


Test Yourself: (why not try testing your skill on this subject? Clicking the link will start the test.)
VB Potpourri: Programming, History And Syntax by batterseapower

A nice little collection of the basics of Visual Basic.
Advanced Programming Techniques by batterseapower

A fiendish test covering some of the more obscure elements of Visual Basic 6.


     
Your Ad Here
 
Copyright Open Source Institute, 2006