Why 0 is considered 'Empty' in VBA?

[Akuini]

Why 0 is considered 'Empty' in VBA?
I ran this macro:

Sub test1()
Dim x As Variant
x = 0
Debug.Print IsEmpty(x)  'returns  False
Debug.Print x = Empty   'returns  True
End Sub

Using IsEmpty(x) returns 'False' as I expected, but why x = Empty returns 'True'?

 

[RoryA]

Because of implicit coercion. "" = Empty will also return True as will Empty = False

 

[Akuini]

Because of implicit coercion. "" = Empty will also return True as will Empty = False

I don't understand, in my code where implicit coercion happens?

 

[RoryA]

As soon as you use x = Empty

You would also find that 1 = "1" was true.

 

[Akuini]

As soon as you use x = Empty

Okay, here's my understanding: because x is 0, it is coerced to False, and 'Empty' is also coerced to False. Therefore, False = False, which returns True.
Is my understanding correct?"

 

[Jaafar Tribak]

Cristian Buse explains this stuff in detail here

Pay special attention to the following section:

Comparing a Variant with Empty is like comparing 2 Variants. When comparing 2 Variants, there are some special rules that apply. Stated here:

If expression1 and expression2 are both Variant expressions, their underlying type determines how they are compared. The following table shows how the expressions are compared or the result from the comparison, depending on the underlying type of the Variant.

If	Then
Both Variant expressions are numeric	Perform a numeric comparison.
Both Variant expressions are strings	Perform a string comparison.
One Variant expression is numeric and the other is a string	The numeric expression is less than the string expression.
One Variant expression is Empty and the other is numeric	Perform a numeric comparison, using 0 as the Empty expression.
One Variant expression is Empty and the other is a string	Perform a string comparison, using a zero-length string ("") as the Empty expression.
Both Variant expressions are Empty	The expressions are equal.

 

[Akuini]

Cristian Buse explains this stuff in detail here

Thanks for the information , I need some time to study it.