Procedure/Function Examples

Example : A program in VB .Net to show both Subroutine and Function Procedure.

Module Module1
    ' Function Procedure Example
    Function Display(ByVal a As Integer, ByVal b As Integer) As Integer
        Return a * b
    End Function

    ' Sub Procedure Example
    Sub Output(ByVal result As Integer)
        Console.WriteLine("The result is: " & result)
    End Sub

    Sub Main()
        Dim num1 As Integer = 10
        Dim num2 As Integer = 5
        Dim product As Integer = Display(num1, num2)
        Output(product)    ' Output: The result is: 50
    End Sub
End Module

Example : A program in VB .Net to show Parameterized Subroutine Procedure.

Module Module1
    Sub StringMessage(ByVal name As String)
        Console.WriteLine("Hello, " & name)
    End Sub

    Sub Main()
        StringMessage("India")
    End Sub
End Module

Example : A program in VB .Net to show Non-Parameterized using Subroutine Procedure.

Module Module1
    Sub Message()
        Console.WriteLine("Hello India")
    End Sub

    Sub Main()
        Message()
    End Sub
End Module

Example : A program in VB .Net to show Optional and Default Parameters using Subroutine Procedure.

Module Module1
    Sub Example(Optional ByVal name As String = "India")
        Console.WriteLine("Hello, " & name)
    End Sub

    Sub Main()
        Example()             ' Output: Hello, India [default parameter]
        Example("World")      ' Output: Hello, World
    End Sub
End Module

NB:
Parameters in a sub procedure can be optional and can have default values.

Example : A program in VB .Net to show Exit Sub Statement using Sub Procedure.

Module Module1
    Sub CheckAge(ByVal age As Integer)
        If age < 18 Then
            Console.WriteLine("Not Eligible for Vote!")
            Exit Sub
        End If
        Console.WriteLine("Eligible for Vote")
    End Sub

    Sub Main()
        CheckAge(50)
    End Sub
End Module

Example : A program in VB .Net to show ByVal (Call by Value) Statement using Sub Procedure.

Module Module1
    ' Define a Sub that uses ByVal
    Sub Calculation(ByVal num As Integer)
        Dim x As Integer = num
        Console.WriteLine("The value after procesing is : " & x)
    End Sub

    Sub Main()
        ' Declare a variable
        Dim Value As Integer = 20

        ' Call the Sub
        Calculation(Value)

        ' Print the original value after the Subroutine call
        Console.WriteLine("Original value before processing : " & Value)
    End Sub
End Module

Output:
The value after procesing is : 20
Original value before processing : 20

Example : A program in VB .Net to show ByRef (Call by Reference) Statement using Sub Procedure.

Module Module1
    ' Define a Sub that uses ByRef statement
    Sub UpdateValue(ByRef num As Integer)
        ' Modify the original variable
        num = num + 50
        Console.WriteLine("Value inside the Sub (ByRef): " & num)
    End Sub

    Sub Main()
        ' Declare an integer variable
        Dim originalValue As Integer = 50

        ' Print the original value before calling/using the Sub
        Console.WriteLine("Original value before Sub call: " & originalValue)

        ' Call the Sub with ByRef
        UpdateValue(originalValue)

        ' Print the original value after calling the Sub
        Console.WriteLine("Original value after Sub call: " & originalValue)
    End Sub
End Module

Output:
Original value before Sub call: 50
Value inside the Sub (ByRef): 100
Original value after Sub call: 100

Example : A program in VB .Net to show Exit Function Statement using Function Procedure.

Module Module1
    Function CheckAge(ByVal age As Integer)
        If age < 18 Then
            Console.WriteLine("Not Eligible for Vote!")
            Exit Function
        End If
        Console.WriteLine("Eligible for Vote")
    End Function

    Sub Main()
        CheckAge(10)
    End Sub
End Module

Example : A program in VB .Net to show No Parameter and No-Return using Function Procedure.

Module Module1
    Function Message()
        Console.WriteLine("Hello India")
        Return 1
    End Function

    Sub Main()
        Message()
    End Sub
End Module

Example : A program in VB .Net to show No Parameter and With-Return using Function Procedure.

Module Module1
    Function Calculation()
        Dim x = 10, y = 20, z As Integer
        z = x + y
        Return z
    End Function

    Sub Main()
        Console.WriteLine("The addition result is = " & Calculation())
    End Sub
End Module

Example : A program in VB .Net to show With Parameter and No – Return using Function Procedure.

Module Module1
    Function Calculation(ByVal x As Integer, ByVal y As Integer)
        Dim z As Integer
        z = x + y
        Console.WriteLine("The addition result is = " & z)
    End Function

    Sub Main()
        Calculation(10, 20)
    End Sub
End Module

Example : A program in VB .Net to show With Parameter and With – Return using Function Procedure.

Module Module1
    Function Calculation(ByVal x As Integer, ByVal y As Integer)
        Dim z As Integer
        z = x + y
        Return z
    End Function

    Sub Main()
        Console.WriteLine("The addition result is = " & Calculation(10, 20))
    End Sub
End Module

Example : A program in VB .Net to show Recursive Function using Function Procedure.

Module Module1
    Function Factorial(ByVal n As Integer) As Integer
        If n = 0 Then
            Return 1
        Else
            Return n * Factorial(n - 1)
        End If
    End Function

    Sub Main()
        Dim result As Integer = Factorial(5)
        Console.WriteLine("The factorial result is: " & result)
    End Sub
End Module

Example : A program in VB .Net to show Shared Function using Function Procedure.

Module Module1
    Class Example
        Shared Function Square(ByVal num As Integer) As Integer
            Return num * num
        End Function
    End Class

    Sub Main()
        Dim result As Integer = Example.Square(5)
        Console.WriteLine("The square value is = " & result)
    End Sub
End Module