Help with code for interest calculation formula visual basic 2008

Im having problems with getting the correct formula for this assignment. I did what the book says and its not working. I have to enter a principal and then in the multiline text box I have to have one column with the rate(%) which are 5,6,7,8,9 and 10 and then the other column has to be the amount after 10 years. It says the interest calculation formula is a=p(1+r)^n. This is what I got so far and nothing is appearing in my multiline text box.
Private Sub calculateButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles calculateButton.Click
        ' Declare Variables
        Dim Principal As Decimal
        Dim Rate As Double
        Dim Amount As Decimal
        Dim Output As String

        ' Retrieve User Input
        Principal = Val(principalTextBox.Text)
        Output = ResultTextBox.Text

        ' Set Output Header
        Output = "Rate(%)" & ControlChars.Tab & ControlChars.Tab & "Amount after 10 years" & ControlChars.CrLf

        ' Calculate Amount
        For years As Integer = 5 To 10
            Amount = _
            Principal * ((1 + Rate) ^ 10)
            Output = ("5" & ControlChars.Tab & ControlChars.Tab & _
                       String.Format("{0:C}", Amount) & ControlChars.CrLf)
        Next
       

    End Sub

Any help please im getting frustrated.
goldfingerpunkAsked:
Who is Participating?

Improve company productivity with a Business Account.Sign Up

x
 
wdosanjosConnect With a Mentor Commented:
That's what you instructed it to print on:

            Output = Output & ("5" & ControlChars.Tab & ControlChars.Tab & _
                       String.Format("{0:C}", Amount) & ControlChars.CrLf)

Try this:

Private Sub calculateButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles calculateButton.Click
        ' Declare Variables
        Dim Principal As Decimal
        Dim Rate As Double
        Dim Amount As Decimal
        Dim Output As String

        ' Retrieve User Input
        Principal = Val(principalTextBox.Text)
        Output = ResultTextBox.Text & ControlChars.CrLf

        ' Set Output Header
        Output = Output & "Rate(%)" & ControlChars.Tab & ControlChars.Tab & "Amount after 10 years" & ControlChars.CrLf

        ' Calculate Amount
        For years As Integer = 5 To 10
            Rate = years / 100
            Amount = _
            Principal * ((1 + Rate) ^ 10)
            Output = Output & (years.ToString() & ControlChars.Tab & ControlChars.Tab & _
                       String.Format("{0:C}", Amount) & ControlChars.CrLf)
        Next
       
        ResultTextBox.Text = Output

    End Sub

Open in new window

0
 
wdosanjosCommented:
Try this:

Private Sub calculateButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles calculateButton.Click
        ' Declare Variables
        Dim Principal As Decimal
        Dim Rate As Double
        Dim Amount As Decimal
        Dim Output As String

        ' Retrieve User Input
        Principal = Val(principalTextBox.Text)
        Output = ResultTextBox.Text & ControlChars.CrLf

        ' Set Output Header
        Output = Output & "Rate(%)" & ControlChars.Tab & ControlChars.Tab & "Amount after 10 years" & ControlChars.CrLf

        ' Calculate Amount
        For years As Integer = 5 To 10
            Amount = _
            Principal * ((1 + Rate) ^ 10)
            Output = Output & ("5" & ControlChars.Tab & ControlChars.Tab & _
                       String.Format("{0:C}", Amount) & ControlChars.CrLf)
        Next
       
        ResultTextBox.Text = Output

    End Sub

Open in new window

0
 
goldfingerpunkAuthor Commented:
It calculated but now the problem is it has one column of all 5's and the other column is the same number too
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.