Lesson 21 - Nullable types, cloning, attributes, destructor and more

In the previous lesson, Structures, boxing, partial members and methods in detail, we introduced some last OOP syntax of Visual Basic .NET. In today's tutorial, we're going to finish it.

Nullable types

We often encounter problems when using value types, especially when it comes to databases. In databases, each column can contain a Nothing value. Unfortunately, the .NET value data types cannot contain that value. We can, however, easily specify a data type as nullable by suffixing the variable name with a question mark. Then, VB.NET allows us to store a null (Nothing) value into variables of that type. You will find that this is a very common practice when working with databases. The value inside a nullable type can be accessed via


 

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This tutorial is the last of the object-oriented programming in VB.NET course. We'll discuss nullable types, cloning, attributes, destructors and more.

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