Efficient, multiple variable declaration & assignment in VB.NET

Question

Being new to VB.NET, I would like to know which of the following is more efficient in nature (time-wise (which code runs faster), code-neatness-wise, etc. you may add your own reasons too)

Dim a, b, c, d As Integer
a = 1
b = 2
c = 3
d = 4

OR

Dim a As Integer = 1
Dim b As Integer = 2
Dim c As Integer = 3
Dim d As Integer = 4

I am mainly asking this because my code has way too many Dim statements & coming from a Python background, I have never ever seen soooo many declarations (I do need those though, trust me). Is this okay? Or am I coding in a bad style?

Answer 1

Runtime performance will be identical, as they both compile to the same IL.

.locals init ([0] int32 a,
       [1] int32 b,
       [2] int32 c,
       [3] int32 d)
IL_0000:  ldc.i4.1
IL_0001:  stloc.0
IL_0002:  ldc.i4.2
IL_0003:  stloc.1
IL_0004:  ldc.i4.3
IL_0005:  stloc.2
IL_0006:  ldc.i4.4
IL_0007:  stloc.3
IL_0008:  ret

Style-wise, I would avoid declaring multiple variables on one line (as in your first example). One "concept" per line is easier to read - as you don't have to visually parse commas.

Answer 2

For the sake of clarity, perhaps one variable per line with an assignment for me personally is easier to look at and much clearer.

I mean you can do this:

Dim a As Single = 1, b As Single = 2, x As Double = 5.5, y As Double = 7.5

Taken from here.

But things start to look a bit difficult at this point. It is entirely a prefernce thing I suppose!

Answer 3

Both options are ok. Still if you are not happy then you can create an array as all variables are of the same data types. Hope that helps.