Checking if the number is decimal

[kpark91]

Hello, I come with another programming question D:

I've been trying to solve Problem 3 of Project Euler with VBA and because I'm still a learner in every programming aspects. If either of these two questions are answered, it would mean ALOT to me

In VBA or any programming languages, when we're using Mod, the numbers have to be low enough to actually perform the function. (and they also need to be integers).

However, my number is too high and it cannot be converted to integers because of overflow. (1) So, is there such a function in VBA that allows me to find the remainder between the two doubles?

As far as I'm concerned, VBA does not have it or any other programming languages. So, this leads to my second question.

(2) How do I check if a double is a decimal number?


Thank you in advance!
kpark

 

[djreiswig]

Maybe not the most elegant way, but can you convert it to a string and see if it contains a decimal point?

 

[shg]

IsWholeNumber = Int(myDbl) = myDbl

 

[GTO]

Not really sure about this, but a chance to learn if I've blown it...

Sub exa4()
Dim dblVal1 As Double, dblVal2 As Double
Dim dblRemainder As Double
    
dblVal1 = 97003.5435
dblVal2 = 89778.0003
    
MsgBox "Double has val after decimal: " & Not CBool(dblVal1 - CLng(dblVal1) = 0)
    
dblRemainder = ((dblVal1 / dblVal2) - CLng((dblVal1 / dblVal2))) * dblVal2
End Sub

 

[kpark91]

djreiswig
oh, yeahh I totally forgot about "." in strings haha. yeah. That would be a good idea :P and I've tried it and it worked!!

shg
Wha... Why did it work lol
I tried it before and it didn't work -_-
I made it as a function where it was this:

Function IsWholeNumber(myDbl As Double)
    IsWholeNumber = Int(myDbl) = myDbl
End Function

GTO
Hello, your decimal thingy works but not the dblRemainder because of overflow.
I am thinking it is because of

CLng(dblVal1 / dblVal2)

The value I am working with is 600851475143 and... it's way over 2 million, which is Long variable's limit.
However, it was working with smaller numbers and I think I can get the remainder after looking at yours.


Thank you very much to all of you for helping me out
They were all different ideas and they were all amazing!

Thanks again,
kpark

 

[shg]

Int doesn't convert a number to Integer (that's CInt).

You could use this for the MOD function:

Function myMod(d1 As Double, d2 As Double) As Double
    ' Returns MOD(d1, d2)
    myMod = d1 - Int(d1 / d2) * d2
End Function

 

[Scott Huish]

GTO:

Your use of CBool is redundant:

This is already a Boolean Expression:

dblVal1 - CLng(dblVal1) = 0

 

[kpark91]

shg
Oh... lol. I have made the problem more complicated on my own...
Gahh this is embarassing xD
Thank you very much!
I was working on this problem for like an hour now...

 

[GTO]

Hi shg,

For whatever reason, I have always assumed Int() could run into overflow (probably the name), but I see that this is incorrect. Am I correct in presuming it simply truncates without limitation to size of number?

Thanks,

Mark

 

[GTO]

Oops. Thank you HotPepper, I had not seen your post.