Imports System

​

Public Module Module1

    Public Sub Main()

        Dim val As Double = 1.5

        Console.WriteLine("val starts as " & val)

        ChangeValueTypePassedByValue(val)

        Console.WriteLine("val passed by value is now " & val)

        val = 1.5

        Console.WriteLine("val starts as " & val)

        ChangeValueTypePassedByReference(val)

        Console.WriteLine("val passed by reference is now " & val)

        Dim ref As New MyRefType(1.5)

        Console.WriteLine("ref starts as " & ref.Val)

        ChangeReferenceTypePassedByValue(ref)

        Console.WriteLine("ref passed by value is now " & ref.Val)

    End Sub

    Private Sub ChangeValueTypePassedByValue(ByVal arg As Double)

        arg = arg + 1

    End Sub

    Private Sub ChangeValueTypePassedByReference(ByRef arg As Double)

        arg = arg + 1

    End Sub

    Private Sub ChangeReferenceTypePassedByValue(ByVal arg As MyRefType)

        arg.Val = arg.Val + 1

    End Sub

End Module

​

Public Class MyRefType

    Public Val As Double

    public Sub New(v as Double)

        Val = v

    End Sub

End Class