How could I display results of an operation to a text file temporarily?

[NEBozman]

I am writing my own script for a simple calculator that determines if a number is prime, and its prime factors. Currently my code looks like:

 Private Sub primebutton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles primebutton.Click
        Dim oWrite As System.IO.StreamWriter
        oWrite = File.CreateText("C:\TempFactors.txt")
        TestLabel.Text = ""
        'Determines perfect square qualifications on following 5 lines
        Dim root As Double
        Dim compare As Integer
        root = System.Math.Sqrt(answer)
        compare = CInt(CLng(root) \ 1)
        If root = compare Then TestLabel.Text = "Perfect Square Composite (Not Prime)"
        'Determines if number is prime
        Dim n1 As Double
        Dim n2 As Double
        Dim n3 As Double
        Dim loopcount As Double
        n3 = compare / 1
        loopcount = compare - 2
        Do Until loopcount = 0
            n1 = answer / n3
            n2 = CLng(n1) \ 1
            If n1 = n2 Then oWrite.Write(n2.ToString, n3.ToString)
            End
            loopcount = loopcount - 1
        Loop
        oWrite.Close()
    End Sub

The loopcount = compare - 2 means I want the loop to be 2 less than the square root of the answer so that when do a descending calculation (loopcount = loopcount - 1) it doesn't see if 1 or 0 is a factor of the answer. for the calculations after that, I want, every time n1 = n2 (a whole number factor of the answer), I want to report those results to a text file (n2 and n3) in this format "(n2, n3)" then go to the next line. and continue to execute the loop until the loopcount is zero. Currently, when I run the code, the application closes when I click the prime button (button that runs this code) and I don't know why. This is my first semester in school, and have never coded before, so I am a definite laymen with code, but I really really want to learn it (hence why for fun im just creating algorithms for different things). Please help!! What did I do wrong and how can I fix this problem. Thanks in advance.

-Nick

[tlhintoq]

But I can make some suggestions.

• Assume that everything is broken, or at least not ideal.
• Presume that the user is going to provide data in a format or manner that you just didn't expect. If you use a textbox for a number, the user will type "One".
• Assume that hardware breaks in the middle of what you are doing, so you have to recover.
• Take a few extra lines of code to get standards like the boot drive, the number thousands seperator etc. Don't assume that you have a C: drive or that a comma is the separator because not everyone is in America.
• Check that folders exist, even if you just did a call to make it: You may not have permissions.
• Get used to placing breakpoints and walking through the code line by line. Double check EVERYTHING on every line. Keep the "Locals" and "Autos" windows open so you can see your values.
  
  • Put a breakpoint on line 1.
  • When the code stops there, walk through line by line with F-10.
  • Check the values of your assumptions.
• Stop. Breath. Relax. Then reason out the problem. Cut it down by sections or halves. "The value was good here, then at this method it wasn't. Where did it go between 'A' and 'B'?"
• Range check and validate values. Confirm that you didn't get a zero when you are only set to accept 1-10. Confirm your objects and values aren't null. Initialize them to a known default if possible. If a selection can be from 0-10, then initialize to -1: Now you have something to check for.

[tlhintoq]

TIP: When you are writing your question, there is a button on the tool bar that wraps the [code] tags around your copy/pasted code. It helps a bunch. Its the button with a '#' on it. More on tags. They're cool. Check'em out.