ComboBox load problem

M

mollin1

New Member
Licensed User
Hi all,

I'm using Basic4PPC V6.05 and want to load a ComboBox with a series of items (sample code is below).

Sub App_Start
Form1.Show
For i = 1.01 To 12 Step 0.01
If i = 1.45 Then
ComboBox1.Add (i & " xxx")
Else
If i = 2.5 Then
ComboBox1.Add (i & " xxx")
Else
ComboBox1.Add(i)
End If
End If
Next i
ComboBox1.SelectedIndex = 399 ' default display = 5 = index 399
End Sub

If I run the above inside the IDE its fine but when compiled to either device or desktop the combobox loads ok to "2.27" and the next value becomes "2.2799999999".

The extra 0.009999999999's are then added to all subsequent items in the ComboBox.

Any suggestions to solve this problem?

Thanks in advance

mollin1
 
agraham

agraham

Expert
Licensed User
Longtime User
Use Round(i,2) to get the result you want. See Help->Main Help->Keywords->Math

What you are seeing is due to the fact that binary floating point numbers used for general purposes in computers cannot always exactly represent non-integer real decimal numbers. Where exact precision is needed computer languages offer special numeric types such as "Currency" or "Decimal" where the results of operations using such numbers is guaranteed to be as expected.

EDIT :- Damn, second again! :)
 
M

mollin1

New Member
Licensed User
Many thanks for your high speed replies guys, both for the tip and the explanation...!

I'll try it out now...
 
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