Decimals bug??

[Emilio Dabdoub]

I'm having a problem doing a simple addition in VB.NET
?84.16+39.57
123.72999999999 999

it should be: 123.73

Where is vb.net getting all this decimals?

Any help will be appreciated.

Thanks

[Cor Ligthert]

Re: Decimals bug??

Emilio,

One of the first things if you not are upgrading is setting in the options
or in the top of your program files.

Option Strict On

You will see than that you cannot do what you write, because you are adding
doubles.

I hope this helps,

Cor

[Cor Ligthert]

Re: Decimals bug??

Emilio,

I forgot, please don't write about a bug if you are not sure of that, if
everybody start telling that it is bug, than Microsoft will sure not take
notice from that in this newsgroup.

Thanks in advance.

Cor

[Larry Lard]

Re: Decimals bug??


Emilio Dabdoub wrote:[color=blue]
> I'm having a problem doing a simple addition in VB.NET
> ?84.16+39.57
> 123.72999999999 999
>
> it should be: 123.73
>
> Where is vb.net getting all this decimals?[/color]

I've got a better one!

?0.1+0.1+0.1-0.3
0.0000000000000 000555111512312 57827
[color=blue]
>
> Any help will be appreciated.[/color]

Don't expect exact results if you use floating-point types.

--
Larry Lard
Replies to group please

[Chris Dunaway]

Re: Decimals bug??

That is just the nature of using floating point numbers in a binary
machine. It happens with all languages not just VB or C#. To avoid
these types of problems, use the Decimal datatype.

[Jay B. Harlow [MVP - Outlook]]

Re: Decimals bug??

Emilio,
In addition to the other comments, check out:

http://www.yoda.arachsys.com/csharp/floatingpoint.html

http://www.yoda.arachsys.com/csharp/decimal.html

| ?84.16+39.57
| 123.72999999999 999

84.16 & 39.57 are doubles, so you are using doubles (binary floating point)
for the calculation.

? CDec(84.16) + CDec(39.57)
123.73D

The doubles are converted to Decimals before the addition, so you are using
Decimal (decimal floating point) for the calculation.

Instead of CDec(84.16) you could have written 84.16, where 84.16D is a
Decimal literal, and 84.16 (or 84.16R) is a Double literal, 84.16F happens
to be a Single literal.

Hope this helps
Jay



"Emilio Dabdoub" <emilio@sandlui s.com> wrote in message
news:O6LIp0kcFH A.3864@TK2MSFTN GP10.phx.gbl...
| I'm having a problem doing a simple addition in VB.NET
| ?84.16+39.57
| 123.72999999999 999
|
| it should be: 123.73
|
| Where is vb.net getting all this decimals?
|
| Any help will be appreciated.
|
| Thanks
|
|