Why is 0 divided by 0 throwing an overflow error in VBA?

Question

Why is 0/0 throwing Overflow error in VBA, while in .Net languages it is simply a Division by 0 error?

E.g., in C# it is a System.DivideByZeroException

static void Main()
{
    int k = 0;
    int p = 0;
    Console.WriteLine(k/p);
}

Div/0 error exists in VBA. But 0/0 gives an overflow exception, while anything else divided by 0 gives a Div/0 exception:

Public Sub TestMe()

    'Integer
    PrintAndCheck (11)      '- Division by zero error

    'Double
    PrintAndCheck (0.9)     '- Division by zero error

    'Long
    PrintAndCheck (50000)   '- Division by zero error

    'String
    PrintAndCheck ("1.1")   '- Division by zero error

    '----------------------------------------------------
    '----------------BUT---------------------------------
    '----------------------------------------------------

    'Integer
    PrintAndCheck (0)       '- Overflow?

End Sub

Public Sub PrintAndCheck(lngDivisor As Variant)

    On Error Resume Next

    Debug.Print lngDivisor / 0
    Debug.Print Err.Description & " from type -> " & VarType(lngDivisor)

    On Error GoTo 0

End Sub

That's what you get in the immediate window:

Division by zero from type -> 2
Division by zero from type -> 5
Division by zero from type -> 3
Division by zero from type -> 8
Overflow from type -> 2

Edit: To make the whole story more interesting:

Public Sub TestMe()
    On Error Resume Next
    Debug.Print Evaluate("0/0")     'Division by 0 error (CVErr(xlErrDiv0)=2007)
    Debug.Print 0 \ 0               'Division by 0 error
    Debug.Print Err.Description
    On Error GoTo 0
End Sub

@meowgoesthedog - in C# it does not compile, in VBA it gives Overflow — Vityata
– Vityata, Commented Aug 3, 2017 at 13:24
If every language behaved identically in all circumstances, there wouldn't be different languages. Since 0/0 is very poorly defined, there no single correct response to it. — Damien_The_Unbeliever
– Damien_The_Unbeliever, Commented Aug 3, 2017 at 13:32
It's an interesting question, which I think would be better if you left C# / .Net exceptions out of it, and re-worded it to compare VBA behavior when dividing by zero with a non-zero numerator VS. a zero numerator. — littlerufe
– littlerufe, Commented Aug 3, 2017 at 13:56
It is worth pointing out that 0 / 0 is a special case. The normal argument against calculations of the form x / 0 where x <> 0 is that there is no number y such that y * 0 = x, and that x / 0 is therefore undefined. This is not the case for 0, as 0 * 0 is indeed 0. So if VBA generates a different error for 0 / 0 as opposed to 1 / 0, I take my hat off to it! — Jonathan Willcock
– Jonathan Willcock, Commented Aug 3, 2017 at 14:18

2 revs · Accepted Answer · 2018-03-12 10:02:06Z

2

Will try to summarize the answers from the comments:

In VBA 0/0 throws an Overflow exception, because 0/0 is a specific case of division by 0. Thus, it is a good idea to throw a different exception than the standard Division by zero error.
In VBA Evaluate("0/0") returns a Division by zero error, because Evaluate does not raise an error, it returns a Variant value with an error flag, and there is no "overflow" flag available.
In VBA integer division 0\0 returns a Division by zero error, because the result should be an integer value and #IND is a floating point value. As far as #IND cannot be returned, it gives the next best thing - Division by zero error.

More reading concerning 0/0 in other languages:

edited Mar 12, 2018 at 10:02

community wiki

2 revs
Vityata

Sign up to request clarification or add additional context in comments.

Comments

Ravi Yenugu · Accepted Answer · 2017-08-03 14:20:53Z

1

https://learn.microsoft.com/en-us/dotnet/visual-basic/language-reference/operators/floating-point-division-operator

Besides the obvious differences in implementation of languages and the way VBA handles division, MS Doc link above expands on the reasons for overflow exception , that if the operand data types are integer then it will throw Overflow exception (Last statement below)

Alternatively there is \ division operator that checks the range for you and throws Division by zero exception

answered Aug 3, 2017 at 14:20

Ravi Yenugu

3,8885 gold badges43 silver badges60 bronze badges

6 Comments

Vityata Over a year ago

That's an interesting reading indeed, but it is for VB.Net. In VBA, a Single, Double or even a String value of 0/0 would throw an Overthrow error.

Ravi Yenugu Over a year ago

Wouldn't division using string become overloaded and converted to number?

John Coleman Over a year ago

@While it is true that this is for vb.net, the rationale for raising an overflow error as opposed to a division by zero error is doubtless the same. Still, it would be good to find a link to the VBA or at least VB6 documentation for this point.

Vityata Over a year ago

@RYenugu - yes. The result would be a number. Or an error :)

Vityata Over a year ago

@RYenugu - I understand, but in VBA zero is an Integer. See the updated version of the question.

|

Collectives™ on Stack Overflow

Why is 0 divided by 0 throwing an overflow error in VBA?

Edit: To make the whole story more interesting:

2 Answers 2

Comments

6 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

Edit: To make the whole story more interesting:

2 Answers 2

Comments

6 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related