Forum Discussion
byref Type Mismatch Error when declaring multiple variables in single row
Hi!
I guess I would need a bit of explanation what actually happens when I declare variables in a single row. If I do so, passing the variable to another Sub in the default ByRef method won't work. I know two possible solutions (workarounds?) for my issue, but I want to understand why it works, and why the original approach does not.
Here is a short code that gives byref type mismatch error when trying to compile:
Sub Macro1()
Dim A, B As Integer
A = 50
B = 10
Macro2 A
Debug.Print A
End Sub
Sub Macro2(ByRef A As Intger)
A = A * 10
End SubOne solution is to declare A and B variables in different rows, like this:
Dim A As Integer
Dim B As Integer
Another solution is if I pass the value of the variable instead of the reference in Macro2, but in that case A won't get the new value:
Sub Macro2(ByVal A As Integer)
A = A * 10
End Sub
I would like to understand why? What happens when I declare the variables at once that prevents the project to get compiled?
Thanks for the explanation!
Unlike most other programming languages, VBA requires that you specify each variable's data type separately when you declare them on a single line. If you don't, they are declared as the default type Variant.
So
Dim A, B As Integeris equivalent to
Dim A As Variant, B As IntegerWhen you call Macro2, the argument that you pass to the ByRef argument A must be Integer (I assume that Intger was a typo). Since A is effectively declared as Variant in the line above, you get a Type Mismatch error.
Solution:
Dim A As Integer, B As IntegerIn this version, both A and B are declared explicitly as Integer.
2 Replies
Unlike most other programming languages, VBA requires that you specify each variable's data type separately when you declare them on a single line. If you don't, they are declared as the default type Variant.
So
Dim A, B As Integeris equivalent to
Dim A As Variant, B As IntegerWhen you call Macro2, the argument that you pass to the ByRef argument A must be Integer (I assume that Intger was a typo). Since A is effectively declared as Variant in the line above, you get a Type Mismatch error.
Solution:
Dim A As Integer, B As IntegerIn this version, both A and B are declared explicitly as Integer.
- I learn something new every day. In this case I had an inappropriate declaration habit so far. Thank you! (indeed, Intger was just a typo)
