Computer Science Canada question on vb so compilicated... need help! |
| Author: | acidburn90 [ Wed Jun 01, 2005 10:17 pm ] |
| Post subject: | question on vb so compilicated... need help! |
im having this problem with a basic calculator program where i declare num as an integer to be the value of the text in the display and num2 as the value of the text in the display after i have added my second number but everytime i click the equals sign it gives me zero i was wondering if anyone knows why this is happening... this is the code: [code] Private Sub eight_Click() display.Text = Str$(8) End Sub Private Sub seven_Click() If display.Text = "+" Then display.Text = Str$(7) Dim num2 As Integer num2 = Val(display.Text) Else display.Text = Str$(7) End If End Sub Private Sub equals_Click() Dim t As Integer t = num display.Text = Str$(t) End Sub[/code] its really simple but i dont know it just isnt working... im a begginner just in case anyone was wondering p.s. the glasses smiley is really the code for "8 )" so it would be Str$ ( 8 ) |
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| Author: | betaflye [ Sat Jun 04, 2005 9:41 am ] |
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A few comments: 1. Use option explicit to not declare variables as they are used, explicitly declare all variables. You're creating a variable with a value of 0 and assigning it to t, as far as I can tell. 2. Use descriptive variable names that follow some sort of naming style, I try to follow the Microsoft one. http://support.microsoft.com/kb/q110264/ 3. This isn't a complete calculator. 4. You don't need a subroutine for each number, use a control array. 5. I don't see where your addition took place. 6. Learn variable scope. A few notes on the code, txtDisplay can be set to Locked = True, this prevents users from directly editing it. Here's some code I hacked out for you. ' Option explicit requires variables to be declared before they are used Option Explicit ' Declaring the numbers used in the calculation as public makes things easier and provides ' an example of variable scope Public dblNum1 As Double, dblNum2 As Double Private Sub cmdClear_Click() dblNum1 = 0 dblNum2 = 0 txtDisplay.Text = "" End Sub Private Sub cmdEquals_Click() Dim lngRetVal As Double dblNum2 = Val(txtDisplay.Text) lngRetVal = dblNum1 + dblNum2 txtDisplay.Text = lngRetVal End Sub Private Sub cmdNumber_Click(Index As Integer) ' Index is the index of the control array that was clicked ' Since an array starts at 0, we cast to string the value of the index + 1 ' and concatinate it to the display txtDisplay.Text = txtDisplay.Text & Str((Index + 1)) End Sub Private Sub cmdPlus_Click() dblNum1 = Val(txtDisplay.Text) txtDisplay.Text = "" End Sub Private Sub Form_Load() ' Not really needed if one assigned values to the command boxes at design time ' however used to illustrate control array Dim intCount, intNumber As Integer For intCount = 0 To (cmdNumber.Count - 1) intNumber = intCount + 1 cmdNumber(intCount).Caption = (intNumber) Next End Sub Good luck with your project, |
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| Author: | acidburn90 [ Sat Jun 04, 2005 4:37 pm ] |
| Post subject: | |
thnx it really helped me |
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