Passing values between subs and/or functions in VB 2005

In the previous post, we showed how to pass values to a Sub or Function and how to pass a value back from a Function. What about passing values back from a Sub? With a Sub, to pass a value to it, we used ByVal to define what we will being passed in. To pass something back out, we will use ByRef.

    Private Sub DoTask()

Dim i1, i2 As Integer

' Initialize the random-number generator.

Randomize()

' Generate random value between 1 And 6.

i1 = CInt(Int((6 * Rnd()) + 1))

DoTask1(i1, i2)

MessageBox.Show(i2.ToString, "Results")

End Sub



Private Sub DoTask1(ByVal intPass As Integer, ByRef intReturn As Integer)

intReturn = intPass + 10

End Sub

Now you might ask, why use a Function when a Sub can do the same thing? Well for very short Subs such as the example, it will not matter. But for longer Subs, the results could be very troublesome. To put it in a nutshell, if you use a Function, it will execute and compleate before the calling Sub or Function goes to the next step. If you use a Sub, the calling Sub or Function will not wait for it to complete before continuing. So now create your own Subs and Functions and get test out passing values for yourself. The ByRef can be used with Functions as well. So don’t be afraid to try using it!

    Private Sub DoTask()

Dim i1, i2 As Integer

Dim s As String

' Initialize the random-number generator.

Randomize()

' Generate random value between 1 And 6.

i1 = CInt(Int((6 * Rnd()) + 1))

s = DoTask1(i1, i2)

MessageBox.Show(i2.ToString, "Results: " & s)

End Sub



Private Function DoTask1(ByVal intPass As Integer, ByRef intReturn As Integer) As String

intReturn = intPass + 10

If intReturn > 13 Then

DoTask1 = "Hi"

Else

DoTask1 = "Low"

End If

End Function

Happy coding

autopilot

@Chike wrote:

Are you sure about this?
Haven’t seen any mention of it in the [url url=ms-help://MS.VSExpressCC.v80/MS.NETFramework.v20.en/dv_vbalr/html/e347d700-d06c-405b-b302-e9b1edb57dfc.htm:2ymeq02r]documentation[/url:2ymeq02r]

nope… i’m not sure… and in fact, if you pass a ByRef object, it is not true. but if you do not pass a byref object, then from experience, i can tell you that the executing code will not wait..

did i state it correctly? nope… and problably still have not… will it, as stated, help some others avoid problems that i was running into when i first started writing apps? i hope so…

am i an authority on the VB (or any other) programming language? by no means!!!! but i do alot of google searches and reading… then i play with codes until i can get it to do what i am trying to do. i have no programming schooling and learned everything i know by trial and error and reading on line. so when i create a post like this, i am by no means trying to state that i have all the answers… the point of this post is to help those with no experience see in a plain english way how to do the basics… and if the explanation is not 100% acurate, then they start out with a slightly wrong definition… but the concept of the post was still grasped and they can start doing things with their programs because now they have the understanding that they can pass objects to and from subs and/or functions.

it was only about 2 or 3 years ago that i started writing any apps… and as i have a fulltime job doing things other then programming, and as i have not taken any classes on programming, i had written this post because it was something that was not made real clear in alot of the information that i was reading.

my hope is that other new hobbiest coders will get a better idea of how they can expand their programs and start sharing with the community. that is why i have shared not only compiled programs, but alot of my code as well… is my code perfect? probably not even close… but if it can help others who in turn help more, then thats what it is all about…