Resolved Dim As *?*

[Dimuthu93]

hey guys
im new to the proggramming world, in fact i only began last month when i joined our year ten CP class, well anyway, i have a question, our teacher gave us this assignment, we had to create a grade calculator, seems easy enough (like put in 20/40 come out 50%) . heres what i had done

Dim Mark As Decimal
Mark = txtMark.Text
lblMark.text = FormatPercent(Mark)

What have i done wrong?
How can i fix it?
Please help

 

[JuggaloBrotha]

I dunno what your FormatPercent() function does but the code you've posted would need to be changed to something like this for starters:

Dim Mark As Decimal
If Decimal.TryParse(lblMark.Text.Trim, Mark) Then lblMark.Text = FormatPercent(Mark)

 

[Dimuthu93]

I tried what you had written the following error message occured:

Conversion from string "12/24" to type 'Decimal' is not valid.

Thanks for trying though, also how do you get the coding to appear like that?

 

[Solitaire]

First of all, put Option Strict On at the very top of your code. This will enforce explicit type conversion and avoid a lot of errors.

You cannot save text from a textbox to a number directly. You need to save it to a string variable. Then you can convert the string to a number with the TryParse method.

Why are you using the Decimal number type? That should only be used for very large currency values. Use the Double type instead for a fractional number like a percentage. Furthermore, the percent figure should be divided by 100.

Example:

Dim mark As Double
Dim smark As String
smark = txtMark.Text
Double.TryParse(smark, mark)
mark = mark / 100
lblMark.Text = mark.ToString("p")

 

[Dimuthu93]

("p")
what does the p mean?

 

[Solitaire]

I revised my post to include a division for the percent figure. When you format a number to a string using the .ToString() method, you can use an argument to display the number in different ways. The "p" displays it as a percentage. Try out the code for yourself:


Option Strict On 'put this line at the very top of your code window

Dim mark As Double
Dim smark As String
smark = txtMark.Text
Double.TryParse(smark, mark)
mark = mark / 100
lblMark.Text = mark.ToString("p")

 

[Dimuthu93]

yay


Thank You very much worked out great