Parsing doubles in vb.NET

[SL33PY]

Hi,

I'm having a problem parsing strings (comming from a flat text input file)
to doubles.

the code:
currentImportDe tail.Result = CType(line.Subs tring(7, 8).Trim(" "),
System.Double)

What is in my Watch:
line.Substring( 7, 8).Trim(" ") "0.006000"
CType(line.Subs tring(7, 8).Trim(" "), System.Double) 6000.0
System.Decimal. Parse(line.Subs tring(7, 8).Trim(" ")) 6000D
cDec(line.Subst ring(7, 8).Trim(" ")) 6000D
cdbl(line.Subst ring(7, 8).Trim(" ")) 6000.0

I tried to use the other parse methods but for an unknown reason the result
is false and I don't know why.

My regional settings are currently Dutch(Belgium), but since he parses the
string to 6000 point 0 and not comma, I doubt that the regional settings are
the reason why it isn't parsing my data like I want.

[SL33PY]

RE: Parsing doubles in vb.NET

For anyone having the same problem:
the solution:

try using : line.Substring( 7, 8).Trim(" ").Replace(".", ",")

Kind regards,
SL33PY

"SL33PY" wrote:
[color=blue]
> Hi,
>
> I'm having a problem parsing strings (comming from a flat text input file)
> to doubles.
>
> the code:
> currentImportDe tail.Result = CType(line.Subs tring(7, 8).Trim(" "),
> System.Double)
>
> What is in my Watch:
> line.Substring( 7, 8).Trim(" ") "0.006000"
> CType(line.Subs tring(7, 8).Trim(" "), System.Double) 6000.0
> System.Decimal. Parse(line.Subs tring(7, 8).Trim(" ")) 6000D
> cDec(line.Subst ring(7, 8).Trim(" ")) 6000D
> cdbl(line.Subst ring(7, 8).Trim(" ")) 6000.0
>
> I tried to use the other parse methods but for an unknown reason the result
> is false and I don't know why.
>
> My regional settings are currently Dutch(Belgium), but since he parses the
> string to 6000 point 0 and not comma, I doubt that the regional settings are
> the reason why it isn't parsing my data like I want.
>[/color]

[Robson]

Re: Parsing doubles in vb.NET

Hold up a second, you are wanting to parse a double? (sorry if I
misunderstood),

You can:

Double.TryParse (theString)

or

Try

Double.Parse(th eString)

Catch theException as SomeExceptionCa ntRemember

End Try


Hope this helps.



"SL33PY" <SL33PY@discuss ions.microsoft. com> wrote in message
news:B578AD49-A36D-451B-883D-FC2244935186@mi crosoft.com...[color=blue]
> Hi,
>
> I'm having a problem parsing strings (comming from a flat text input file)
> to doubles.
>
> the code:
> currentImportDe tail.Result = CType(line.Subs tring(7, 8).Trim(" "),
> System.Double)
>
> What is in my Watch:
> line.Substring( 7, 8).Trim(" ") "0.006000"
> CType(line.Subs tring(7, 8).Trim(" "), System.Double) 6000.0
> System.Decimal. Parse(line.Subs tring(7, 8).Trim(" ")) 6000D
> cDec(line.Subst ring(7, 8).Trim(" ")) 6000D
> cdbl(line.Subst ring(7, 8).Trim(" ")) 6000.0
>
> I tried to use the other parse methods but for an unknown reason the
> result
> is false and I don't know why.
>
> My regional settings are currently Dutch(Belgium), but since he parses the
> string to 6000 point 0 and not comma, I doubt that the regional settings
> are
> the reason why it isn't parsing my data like I want.
>[/color]

[Cor Ligthert [MVP]]

Re: Parsing doubles in vb.NET

Sl33PY,

Can you give us an idea what the string can looks like?

However, I see that you are using a string with a dot as comma seperator.

AFAIK, is that in the Dutch language for all three cultures a comma.

Dim dbl As Double = CDbl("abcd100,1 0".Substring (4, 5))

This gives for me 100.1

Cor

"SL33PY" <SL33PY@discuss ions.microsoft. com> schreef in bericht
news:B578AD49-A36D-451B-883D-FC2244935186@mi crosoft.com...[color=blue]
> Hi,
>
> I'm having a problem parsing strings (comming from a flat text input file)
> to doubles.
>
> the code:
> currentImportDe tail.Result = CType(line.Subs tring(7, 8).Trim(" "),
> System.Double)
>
> What is in my Watch:
> line.Substring( 7, 8).Trim(" ") "0.006000"
> CType(line.Subs tring(7, 8).Trim(" "), System.Double) 6000.0
> System.Decimal. Parse(line.Subs tring(7, 8).Trim(" ")) 6000D
> cDec(line.Subst ring(7, 8).Trim(" ")) 6000D
> cdbl(line.Subst ring(7, 8).Trim(" ")) 6000.0
>
> I tried to use the other parse methods but for an unknown reason the
> result
> is false and I don't know why.
>
> My regional settings are currently Dutch(Belgium), but since he parses the
> string to 6000 point 0 and not comma, I doubt that the regional settings
> are
> the reason why it isn't parsing my data like I want.
>[/color]

[Armin Zingler]

Re: Parsing doubles in vb.NET

"SL33PY" <SL33PY@discuss ions.microsoft. com> schrieb[color=blue]
> Hi,
>
> I'm having a problem parsing strings (comming from a flat text input
> file) to doubles.
>
> the code:
> currentImportDe tail.Result = CType(line.Subs tring(7, 8).Trim(" "),
> System.Double)
>
> What is in my Watch:
> line.Substring( 7, 8).Trim(" ") "0.006000"
> CType(line.Subs tring(7, 8).Trim(" "), System.Double) 6000.0
> System.Decimal. Parse(line.Subs tring(7, 8).Trim(" ")) 6000D
> cDec(line.Subst ring(7, 8).Trim(" ")) 6000D
> cdbl(line.Subst ring(7, 8).Trim(" ")) 6000.0
>
> I tried to use the other parse methods but for an unknown reason the
> result is false and I don't know why.
>
> My regional settings are currently Dutch(Belgium), but since he
> parses the string to 6000 point 0 and not comma,[/color]

What do you mean with this? The IDE always shows as ".", not a ",", no
matter where you live. This does not mean that it recognizes the "." as a
decimal separator.

[color=blue]
> I doubt that the
> regional settings are the reason why it isn't parsing my data like I
> want.[/color]


I think it is culture dependent.

Try this instead:

dim s as string

s = line.Substring( 7, 8).Trim
currentImportDe tail.Result = double.parse( _
s, System.Globaliz ation.CultureIn fo.InvariantCul ture.NumberForm at) _
)



Armin

[Armin Zingler]

Re: Parsing doubles in vb.NET

"SL33PY" <SL33PY@discuss ions.microsoft. com> schrieb[color=blue]
> For anyone having the same problem:
> the solution:
>
> try using : line.Substring( 7, 8).Trim(" ").Replace(".", ",")[/color]


You know that this code doesn't work region independent? On a machine with
English regional settings, the code would fail because you rely on the
regional settings of the current machine whereas you have a region
independent setting (English) in the text file.


Armin

[Armin Zingler]

Re: Parsing doubles in vb.NET

"Armin Zingler" <az.nospam@free net.de> schrieb[color=blue]
> "SL33PY" <SL33PY@discuss ions.microsoft. com> schrieb[color=green]
> > For anyone having the same problem:
> > the solution:
> >
> > try using : line.Substring( 7, 8).Trim(" ").Replace(".", ",")[/color]
>
>
> You know that this code doesn't work region independent? On a
> machine with English regional settings, the code would fail because
> you rely on the regional settings of the current machine whereas you
> have a region independent setting (English) in the text file.[/color]


Correction:
....you have a region *dependent* setting (English) in the text file.



Armin

[Cor Ligthert [MVP]]

Re: Parsing doubles in vb.NET

Armin,
[color=blue]
> s = line.Substring( 7, 8).Trim
> currentImportDe tail.Result = double.parse( _
> s, System.Globaliz ation.CultureIn fo.InvariantCul ture.NumberForm at) _
> )[/color]

The InvariantCultur e is the same culture as 'en-*' in my opinion not really
usefull here, it makes the program again culture dependend because in AFAIK
all English language cultures the dot is the comma seperator.

Cor

[Cor Ligthert [MVP]]

Re: Parsing doubles in vb.NET

Armin,

With the same reply as you do it yourself, in this case it would work,
however that does the solution from the OP as well.

Cor

[Armin Zingler]

Re: Parsing doubles in vb.NET

"Cor Ligthert [MVP]" <notmyfirstname @planet.nl> schrieb[color=blue]
> Armin,
>
> With the same reply as you do it yourself, in this case it would
> work, however that does the solution from the OP as well.[/color]

??
The format in the text file is always English. InvariantCultur e is always
English, too. Thus, it *always* works. The OP's solution not always works.


Armin

[Armin Zingler]

Re: Parsing doubles in vb.NET

"Cor Ligthert [MVP]" <notmyfirstname @planet.nl> schrieb[color=blue]
> Armin,
>[color=green]
> > s = line.Substring( 7, 8).Trim
> > currentImportDe tail.Result = double.parse( _
> > s,
> > System.Globaliz ation.CultureIn fo.InvariantCul ture.NumberForm at) _
> > )[/color]
>
> The InvariantCultur e is the same culture as 'en-*' in my opinion not
> really usefull here, it makes the program again culture dependend[/color]

Yes, but it has to be culture dependend.
[color=blue]
> because in AFAIK all English language cultures the dot is the comma
> seperator.[/color]

That's why InvariantCultur e is useful because the text file always uses the
dot.

BTW, "the dot is the comma separator" is really nice. :-)


Armin

[Robson]

Re: Parsing doubles in vb.NET

I don't think you can have it both ways. You can't ask the program to run
in many varied cultures and yet import correctly formats from different
cultures again. This numeric information, if it's being used
across-cultures, needs to carry it's culture around with it, so you can
choose the correct culture to use for parsing. Either that or as Armin
says, you need to standardize on the invariant culture whereever your
software is being used.

"Armin Zingler" <az.nospam@free net.de> wrote in message
news:e66fe7M9FH A.1028@TK2MSFTN GP11.phx.gbl...[color=blue]
> "Cor Ligthert [MVP]" <notmyfirstname @planet.nl> schrieb[color=green]
>> Armin,
>>[color=darkred]
>> > s = line.Substring( 7, 8).Trim
>> > currentImportDe tail.Result = double.parse( _
>> > s,
>> > System.Globaliz ation.CultureIn fo.InvariantCul ture.NumberForm at) _
>> > )[/color]
>>
>> The InvariantCultur e is the same culture as 'en-*' in my opinion not
>> really usefull here, it makes the program again culture dependend[/color]
>
> Yes, but it has to be culture dependend.
>[color=green]
>> because in AFAIK all English language cultures the dot is the comma
>> seperator.[/color]
>
> That's why InvariantCultur e is useful because the text file always uses
> the
> dot.
>
> BTW, "the dot is the comma separator" is really nice. :-)
>
>
> Armin
>[/color]

[Cor Ligthert [MVP]]

Re: Parsing doubles in vb.NET

Armin,

You are right, the OP solution will work in our cultures if it is either a
dot or a comma as decimal seperator.

The cultureInvarian t will forever work if the dot is used (en-*) as decimal
separator in every culture.

Cor

[Armin Zingler]

Re: Parsing doubles in vb.NET

"Robson" <nonono@nomeans no.com> schrieb[color=blue]
> I don't think you can have it both ways. You can't ask the program
> to run in many varied cultures and yet import correctly formats from
> different cultures again. This numeric information, if it's being
> used
> across-cultures, needs to carry it's culture around with it, so you
> can choose the correct culture to use for parsing. Either that or
> as Armin says, you need to standardize on the invariant culture
> whereever your software is being used.[/color]


I'm not sure which posting you are referring to. I don't see a problem here:
The application can be region independent and still read region dependent
text files. For example, parsing input in textboxes can be done with
double.parse w/o an explicit culture information. This uses the current
culture and makes the application and it's usage culture independent. The
same application reads from a text file. As a programmer, you must know the
format of the numbers in the file. If you know that it is English, the
invariant culture should be used to parse the values.


Armin

[Herfried K. Wagner [MVP]]

Re: Parsing doubles in vb.NET

"Cor Ligthert [MVP]" <notmyfirstname @planet.nl> schrieb:[color=blue][color=green]
>> s = line.Substring( 7, 8).Trim
>> currentImportDe tail.Result = double.parse( _
>> s, System.Globaliz ation.CultureIn fo.InvariantCul ture.NumberForm at) _
>> )[/color]
>
> The InvariantCultur e is the same culture as 'en-*' in my opinion not
> really usefull here, it makes the program again culture dependend because
> in AFAIK all English language cultures the dot is the comma seperator.[/color]

Well, but it's necessary to use a single, non-ambiguous format when
exchanging data in text files.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>