Hello! I have become somewhat unsure of certian things regarding the syntax
in vba. therefor I would truly appreciate answers to the following questions:

1) In the beginning of a sub that takes two arguments do you have to write:
Private Sub checkReturnDifference(ByVal rng1 As Range, ByVal rng3 As Range)
or can you write ....(ByVal rng1, rng3 As Range)

2) When declaring new variables is it necessary to write:
Dim i As Integer
Dim k As Integer
.....
or is there a shorter way of doing this?

I know that these questions does not seem very important but when you have
meny variables then it does actually make a difference. thus, any help
appreciated! thank you all very much!