Constructor in vb.net

We will know how to use constructor and destructor in a windows application. 

Constructor 

Constructor is special method, which controls over the initialization of object. It is used for variable initialization. When we create an object of the class then the constructor within the class is automatically called. It is used with the keyword new before sub in vb.net

There are two types of constructor
1.Shared constructor
2.Instance constructor

Shared constructor: -  
1.It is used to initialize only shared variables.
2.These are run only once during a single execution.
3.These constructors always get first preference in comparison to instance constructor.
4.These are used by the keyword shared before sub new.
5.It cannot take parameters.

Instance constructors: - 
1.They are used to initialized instance variable ex dim, public, protected, friend, protected friend and private variable.
2.It can also initialize shared variable.
3.It can take parameters.

Ex: - How to declare Instance and shared constructors

    Public Class raj
        Public Sub New()
            MsgBox("Instant constructor of raj")
        End Sub
        Shared Sub New()
            MsgBox("Shared constructor of raj")
        End Sub
    End Class



Ex 
Public Class Form1
    Inherits System.Windows.Forms.Form

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim a As New raj
        a.kunal()
        Dim b As New rahul("pintu")
        Dim c As New rahul(10, 10)
    End Sub
    Public Class raj
        Public Sub New()
            MsgBox("Hello raj constructor")
        End Sub
        Public Sub kunal()
            MsgBox("Hello kunal")
        End Sub
    End Class
    Public Class rahul
        Public Sub New(ByVal x As String)
            MsgBox("Hello" & x)
        End Sub
        Public Sub New(ByVal x As Integer, ByVal y As Integer)
            MsgBox(x + y)
        End Sub
    End Class
End Class