CODEWITHSUNDEEP
vb6localizationtype-conversion
Eric Liprandi
Eric Liprandi

Reputation: 5574

VB6 - converting string to double using specific culture?

I am a long time C# developer and have had to look at some VB6 code lately. After some digging, we found out that, somewhere, somehow, we are storing a number as a string. Now we are reading it back and our code is not handling culture differences very well. Here is an example:

Dim text as String
Dim myVal as Double
Set text = "1,123456"
'This sets the value of myVal to 1123456 on our system - incorrect
myVal = text

Set text = "1.123456"
'This sets the value of myVal to 1.123456 on our system - correct
myVal = text

Keeping in mind that this is VB6 and NOT VB.NET, are there any built-in methods, functions, whatever, that can convert a string to a double using a particular culture? Or at the very least, hinting to the conversion that we may be dealing with a different format?

We are still digging how the value gets written and see if we can reverse engineer the process to give us a consistent result. However, our customer(s) already has(have) data in one format or the other (or both, we are checking...), so a proper conversion algorithm or implementation would be a better answer at this point.

Upvotes: 3

Views: 8873

Answers (3)

Roy
Roy

Reputation: 1

In Visual Basic tested works very fast and efficient.

Step 1: Conversion from a string to a value representation.

Step 2: Conversion from a value representation to a double integer value. 

Dim Str as String
Dim mValue as double
str = "100,10"

mValue = CDbl(Val(str))

Upvotes: 0

MarkJ
MarkJ

Reputation: 30408

You cannot choose an arbitrary culture by passing a culture object like you can in .Net. You can choose:

  • Functions which always use the current regional settings. CStr, Format, CDbl etc. Implicit conversions (like the ones in your question) also use the current regional settings.
  • Functions which always use USA regional settings (similar to the .Net invariant culture). Str, Val

Usually the current regional settings are taken from Control Panel. There are rumours that you can call SetThreadLocale to change the regional settings from code at runtime - never tried it myself.

Upvotes: 3

Eduardo Molteni
Eduardo Molteni

Reputation: 39443

I've used this quick and dirty function in the past to get a double from a text. Here in Argentina, people sometimes use the point and sometimes the comma to separate decimal values, so this function is ready to accept both formats. If only one punctuation is present, it's assumed that it's the decimal separator.

function ConvertDBL( texto )
    dim retval, SepDecimal, SepMiles
    If texto = "" then texto = "0"
    retval = replace(trim(texto), " ", "")
    If cdbl("3,24") = 324 then
        SepDecimal = "."
        SepMiles = ","
    else
        SepDecimal = ","
        SepMiles = "."
    end if  
    If InStr( Retval, SepDecimal ) > 0 then
        If InStr( Retval, SepMiles ) > 0 then
            If InStr( Retval, SepDecimal ) > InStr( Retval, SepMiles ) then
                Retval = replace( Retval, SepMiles, "" )
            else
                Retval = replace( Retval, SepDecimal, "" )
                Retval = replace( Retval, SepMiles, SepDecimal )
            end if
        end if      
    else
        Retval = replace( Retval, SepMiles, SepDecimal )
    end if
    ConvertDbl = cdbl( retval ) 
end function

Upvotes: 8

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