Visual Basic .NET/Inheritance

Inheritance Inheritance is mainly used to reduce duplication of code. By using the Inherits keyword, you can extend and modify an existing class to have additional properties and methods. For example, imagine we have an existing class called "Person": Public Class Person Public FirstName As String Public LastName As String Public DateOfBirth As Date Public Gender As String Public ReadOnly Property FullName() As String Get Return FirstName & " " & LastName End Get End Property End Class Now imagine we wanted to create a special class called "Customer", which had all the properties of "Person", but also additional properties called "CustomerID" and "CustomerType". We could just make a different class with similar properties as follows: Public Class Customer Public FirstName As String Public LastName As String Public DateOfBirth As Date Public Gender As String Public ReadOnly Property FullName() As String Get Return FirstName & " " & LastName End Get End Property Public CustomerID As String Public CustomerType As String End Class An alternative approach, however is to use the Inherits keyword as follows: Public Class Customer Inherits Person Public CustomerID As String Public CustomerType As String End Class "Inherits Person" automatically gives the new "Customer" class all the properties and methods of the "Person" class, as well as the two new properties. This approach also has several advantages: We don't have to re-type the FirstName, LastName, DateOfBirth etc properties When properties and methods of the "Person" class are updated, the "Customer" class need not be rewritten as well. The .FullName property needs to be debugged in only one place Any code that uses a "Person" object can also use a "Customer" object. fr:Visual Basic .NET/Héritage