[AdamSpeight2008]

I been wondering for a quite a while what VariableName:= was used for when you entering the values of parameter of a subroutine, function or method.
Today I realized what they are used for. So I wrote this tutorial so you can understand them too.

Named Parameters

To explain them, imagine that in your code you have the following routine. (Without using Named Parameters)
I know it's a bit simple but the principles that count in this tutorial

Private Function Divide(Byval Divider as Double, ByVal Divisor As Double) As Double
 ' Work out the quotient
 Return Divider / Divisor
End Function

And you use it like.

Dim A As Double =10
Dim B As Double =2
Dim C As Double = Divide(A,B)

Without using Intellisense what A & B are being using for by the Divide Function is a bit hard.
In this example you could probably guess but what if the function was called xyz it is a lot harder.


But by using named parameters it's a lot easier.

Dim A As Double =10
Dim B As Double =2
Dim C As Double = Divide(Divider:=A,Divisor:=B)

Which is saying;-
The Divide function's Divider parameter is the contents of variable A
The Divide function's Divisor parameter is the contents of variable B


Another Example

 Private Sub PrintHello(ByVal DoYouWantTheHello As Boolean)
  If DoYouWantTheHello =True Then
   Console.WriteLine("Hello World")
  Else
   Console.WriteLine("World")
  End If
 End Sub

PrintHello(DoYouWantTheHello:=True)

Using this alongside with using good variable names makes, in my opinion, the code a lot easier to understand by looking at it.

[LemonMan]

Wow, that could really help me. Thanks!

[Lumenii]

Good to know. I'll definitely be using this. I teach (informally) some VB.NET/ASP.NET, and this would make things clearer for some.

[Steven.James]

Thanks(person:=AdamSpeight2008, from:=Steven.James)

[trythis]

Thanks!