IF statement NOT WORKING! URGENT

[AFish]

Hi Guys

I know this should be simple but it just refuses to work,dont know what I'm missing.
I have this If statement

IF AmountPaid >= Currentbalance Then

My problem is that when the value for AmountPaid is equal to CurrentBalance the condition returns false,when it should be true.

The values for both variables i'm using is 20 which is double, and the variables are passed ByReference into a sub.
This is driving me crazy,PLEASE HELP,i need to solve this URGENTLY.

THANKS

[doofusboy]

Have you tried:

IF (AmountPaid > Currentbalance) OR (AmountPaid = Currentbalance) Then

?

[Pasvorto]

Have you tried moving them ByValue? Or moving them to variables and using the variables ByValue?

[bpd]

Welcome to the world of floating point arithmetic - where nothing is what it seems.

Your problem stems from the fact that decimal numbers aren't always exactly represented correctly in Doubles (or Singles). There are two ways to correctly check for equality:

1) Test within a very small range.
2) Round to a certain # of decimal places before testing.

An example of #1:

If Abs(AmountPaid - Currentbalance) < 0.0001 Then

An example of #2:

If Round(AmountPaid , 2) >= Round(Currentbalance, 2) Then

[si_the_geek]

bpd is completely correct for floating point, but can I just ask why you are using it in the first place?

It seems to me as though the Currency data type (which doesn't have these issues) would be more appropriate.

[dsheller]

Do other languages have these problems? Or is it just something that is isolated to VB?

[bpd]

Do other languages have these problems?

Yes. I've run across this same issue in FORTRAN - a language designed primarily for numeric computations.

[dsheller]

Hmm, quite odd, I've never had such a problem as this in VB, but then again I try to limit the use of doubles/singles whenever possible.

[leinad31]

Since your working with monetary values, try CCur() >= CCur() first before rewritting all those variables.

[MikkyThomeon]

Seeing that there is a slight chance that I actually wrote the part of the code that calcualtes the cost, interest and capital, in any order, you sould email me that section of the code. and I will fix it.

First off - I am here to help you dude.... I cannot contact you by email because MF monitors the mail server. Wow. Big deal. I have lost your cell number so give me an sms or email me at mikethomson at websurfer.co.za. I am there to steal code either. I only use my own code as a rule, although there are a few really good coders on this forum that I really do trust!!!!

PS: Dont believe what MF said - he was just really disappointed that I left. What sort of a compay do you work for that they will retrnch you rather than offer you better training??? I left because the huge program you are working on is single tier (20000+ lines of sinlge tier code!!!) with no planning and no structure. And the lack of progress on it was starting to make me look like an idiot, and this was not fair because I took over the code from two other developers who had no planning or documentation. I gave my recommendation to modulaizre the code but your managament did not agree with me. Without modularizing the code, and you working on the project, there was actually no room for me to work on it. It was impossible to split tasks. Another thing is that my being there was stinting your development.

Secondly the app should rather have been written in php. This way it could have been easier than VB. I am now fully proficient in writing php applications, and have learnt spans about genuine MySQL security(setting database permissions for users that was not done initially). With my ability you could convert that app into a web based app and offer it locally on your LAN or just as easily load it onto your web server.

After 6 months on my own I have really learnt how to modularize software and by doing this I have finally managed to reduce the time take for each module to about 7 days at run.

Pretty soon I will be in Ladysmith and there are a few other excellant business opportunities there. Greed never drove me before but it is starting to become a factor.