PRB: CSng/CDbl Not Using Regional Settings for Decimal Symbol

When you change the Regional Settings to make the Number's decimal symbol the same as the Currency's "digit grouping symbol," CSng does not interpret this character as a decimal point. Therefore, you get a different result that you would have in Visual Basic 5.0. This is also the case for the CDbl function.

The new oleaut32 checks to see if the character is the Currency "digit grouping symbol" first. If it is, then even if it's also the Number's decimal symbol, it will be considered as the Currency "digit grouping symbol" instead of the Number's decimal symbol.

Resolve the conflicting by using the Regional Settings in the Control Panel on the Start menu.

This behavior is by design.

This new behavior is an enhancement, because the String you want to change to a Single value may represent Currency, so it should be transformed to a correct value. If you choose default settings for the locale, the decimal point symbol is always different than that used as the digit grouping symbol of Currency. So this problem only happens when one of these two settings is manually changed, creating a conflict. Having conflicting symbols is not valid (not just in this situation, but also in other situations) and will probably cause other problems as well.

Steps to Reproduce Behavior

1. Create a Standard EXE project. Form1 is created by default.
2. Add a CommandButton to Form1 and place the following code into Form1's code window:

         Private Sub Command1_Click()
            Dim s As Single
            s = CSng("3,5")
            MsgBox s
            s = CSng("3.5")
            MsgBox s
         End Sub
   
   						

3. Click "Start" on the Windows task bar, then Click "Settings" and then "Control Panel." A folder is displayed. Double-click the "Regional Settings" icon and you get a dialog box. Click the "Regional Settings" tab. Choose English (United States) from the drop-down ComboBox. Click "OK" (you may be asked to install the language packages and/or restart your system.) Run the app in Visual Basic 5.0 and in Visual Basic 6.0. You will get consistent results as 35 then 3.5.
4. Return to the Regional Settings as above. Click the Number tab and set the Decimal Symbol to be a comma (,), set the "Digit grouping symbol" to be a period (.), and click OK. Run the app in Visual Basic 5.0 and you get 3,5 and 35 respectively. Run it in Visual Basic 6.0 and you get 35 (which is the new behavior) and 35.