[2005] convert textbox.text to integer

[tomroth]

Hi all!

I need to know how to convert a string that contains operators, such as textbox.text = "3+3+3" to a value that can peform this calculation without any parsing or such.

I know I can type this value into the code window and it would perform this calculation.

Thanks.

[FourBlades]

Can't be done.
You'll have to take it apart and put it back together again using your own logic. Although, this type of thing has been done by other people so maybe you can get a jump start via research.

[Icyculyr]

Well, try this,

Dim sString As String = "3+5+9-2"
Dim sNotNumbers() As String = {"+", "-", "*", "/"}
Dim iInteger As Integer = 0
Dim sSub As String = ""
Dim sPreviousOperator As String = "+"
Dim bPass As Boolean = False
Dim iTempInteger As Integer = 0
For i As Integer = 0 To sString.Length-1
    sSub = sString.Substring(i, 1)
    bPass = False
    If Array.IndexOf(sNotNumbers, sSub) <> -1 Then 'It's not a number
        'Array.IndexOf returns the index of the found item, but -1 if not found
        bPass = True
    End If
    If bPass Then
        sPreviousOperator = sSub
    Else
        If Array.IndexOf(sNotNumbers, sPreviousOperator) = -1 Then
            'Hasn't found the last operator, so it must not be a valid operator
            Throw New Exception(sPreviousOperator & " is not a valid mathematical operator")
        Else
            Select Case sPreviousOperator
                Case sNotNumbers(0) 'Plus in the array
                    iInteger += Integer.Parse(sSub)
                Case sNotNumbers(1) 'Minus
                    iInteger -= Integer.Parse(sSub)
                Case sNotNumbers(2) 'Times
                    iInteger *= Integer.Parse(sSub)
                Case sNotNumbers(3) 'Divide
                    iInteger /= Integer.Parse(sSub)
            End Select
        End If
    End If
Next i

I have not tested this or anything, but it should help you somewhat (I think)

Cheers

[tomroth]

Hey,

Thanks for the response. Works great. But what if I want to add "2.1+3.1"?

It doesn't like decimals. Any short answer?

Thanks!

[Icyculyr]

change iInteger to dDecimal, and search for the "."

or you could use a string to add up the current values, and parse it to an integer when you find an operator..

IE
Dim sString As String = sSub (in replace of iInteger)

And do Dim dDouble As Double = Double.Parse(sString) in the code underneath sPreviousOperator...

Something like that should work,

Cheers