[RESOLVED] Beginner requesting help!

Hi, I'm new to visual basic and I've attempted to make a very simple calculator but I have no idea why it's not working. Of course I've done something stupid but I just can't find it.

The layout of the program is 3 text boxes:
FirstNumber
Operation
SecondNumber

1 Button:
Answer

1 Label:
Answer

The idea is to type in the first number, the operation (*/+-) and the second number, clicking the answer button. Then the label should hold the answer. This is my code:

Dim answerr, operation As String
Dim Firstnumber, Secondnumber As Double
Private Sub cmdAnswer_Click()
Firstnumber = Val(txtFirstnumber.Text)
Secondnumber = Val(txtSecondnumber.Text)
operation = txtOperation.Text
answerr = firstnumber operation secondnumber
Answerbox.Caption = answerr
End Sub


Thanks!

http://www.vbforums.com/attachment.p...id=47243&stc=1

First, while it's not your main problem, when you dim things this way

Dim Firstnumber, Secondnumber As Double

only Secondnumber is a Double - Firstnumber remains a Variant.

The main problem however is that while there are a limited number of things you can do if you want to use strings like "operation", but math operators is not one of them.

You can create a calculator using the MS scripting runtime and if you serach for "calculator" I'm sure you'll find examples.

To do it your way you will need to check the operation string and have a condition for each possible operation you want to be able to perform.
Example:

Select Case operation
Case "+"
answer = firstnumber + secondnumber
Case "-"
answer = firstnumber - secondnumber
'etc
End Select

Quote:

---

Originally Posted by MartinLiss

http://www.vbforums.com/attachment.p...id=47243&stc=1

First, while it's not your main problem, when you dim things this way

Dim Firstnumber, Secondnumber As Double

only Secondnumber is a Double - Firstnumber remains a Variant.

The main problem however is that while there are a limited number of things you can do if you want to use strings like "operation", but math operators is not one of them.

You can create a calculator using the MS scripting runtime and if you serach for "calculator" I'm sure you'll find examples.

---

I never knew that!

Thanks!
[QUOTE:danecook21]
To do it your way you will need to check the operation string and have a condition for each possible operation you want to be able to perform.
Example:

Select Case operation
Case "+"
answer = firstnumber + secondnumber
Case "-"
answer = firstnumber - secondnumber
'etc
End Select
[/QUOTE]

Yeah, in the end I just used radio buttons (I think they're called) and it worked a charm, thanks!