Access modifiers in vb.net with example

Access modifiers in vb.net

Access modifiers define the access to class members from the same class and from other classes. The most common access keywords are:

Public: Allows access to the class member from any other class. 

Example:

Public Class class1

    Public i As Integer

    Public Function raghu() As Integer

        Console.writeline(i)

    End Function

End Class

Module Module1

    Sub main()

        Dim a As New class1

        a.i = 10

        a.raghu()

        Console.ReadLine()

    End Sub

End Module

Output=10
Reason: Allows access to the class member from any other class. 

Private: Allows access to the class member only in the same class. 

Example:

Imports System

Public Class class1

    Private i As Integer

    Public Function raghu() As Integer

        Console.WriteLine(i)

    End Function

End Class

Module Module1

    Sub main()

        Dim a As New class1

        a.i = 10

        a.raghu()

        Console.ReadLine()

    End Sub

End Module

Output: Error (“'ConsoleApplication.class1.i' is not accessible in this context because it is 'Private'.”)
Reason: Allows access to the class member only in the same class. 

Conclusion:

Imports System

Public Class class1

    Private i As Integer = 10

    Public Function raghu() As Integer

        Console.WriteLine(i)

    End Function

End Class

Module Module1

    Sub main()

        Dim a As New class1

        ' a.i = 10

        a.raghu()

        Console.ReadLine()

    End Sub

End Module

Output=10

Protected: Allows access to the class member only within the same class and from inherited classes. 

Example:

Imports System

Public Class class1

    Protected i As Integer

    Public Function raghu() As Integer

        Console.WriteLine(i)

    End Function

End Class

Module Module1

    Sub main()

        Dim a As New class1

        a.i = 10

        a.raghu()

        Console.ReadLine()

    End Sub

End Module

Output=error
Reason: Allows access to the class member only within the same class and from inherited classes.

Conclusion:


Imports System

Public Class class1

    Protected i As Integer = 10

    Public Function raghu() As Integer

        Console.WriteLine(i)

    End Function

End Class

Module Module1

    Sub main()

        Dim a As New class1

        a.raghu()

        Console.ReadLine()

    End Sub

End Module

Output=10

Friend /Internal: Allows access to the class member only in the same assembly. 

Example:

Imports System

Public Class class1

    Friend i As Integer

    Public Function raghu() As Integer

        Console.WriteLine(i)

    End Function

End Class

Module Module1

    Sub main()

        Dim a As New class1

        a.i = 10

        a.raghu()

        Console.ReadLine()

    End Sub

End Module

Ouput: 10
Reason: Allows access to the class member only in the same assembly. 

Protected internal: Allows access to the class member only within the same class, from inherited classes, and other classes in the same assembly. 

Example:

Imports System

Public Class class1

    Protected Friend i As Integer

    Public Function raghu() As Integer

        Console.WriteLine(i)

    End Function

End Class

Module Module1

    Sub main()

        Dim a As New class1

        a.i = 10

        a.raghu()

        Console.ReadLine()

    End Sub

End Module

output:10
Reason: Allows access to the class member only within the same class, from inherited classes, and other classes in the same assembly

Static: Indicates that the member can be called without first instantiating the class.

Static: Indicates that the member can be called without first instantiating the class.

1) Load into memory once (we can save memory)
2) Instance not required