Object Oriented Programming 7 – Constructors

This is the seventh in a series of videos that introduce object oriented programming (OOP) using Visual Basic.NET (VB.NET). This video demonstrates how to write a customised constructor for a class. That is, how to override the New method of a class which is called automatically whenever an object is created. A customised constructor for a class allows property values to be assigned at the time an object is instantiated. This video also shows how a constructor can be overloaded, allowing more flexibility in the way that property values as assigned. It also includes a constructor overload that retrieves the previously saved state of an object from an Access database at the time the object is created. This particular constructor overload is passed a person’s ID number as a parameter, then makes use of ActiveX Data Objects (ADO) to run an SQL select query against the database to fetch the appropriate property values. Later videos in the series will cover inheritance and method overriding.

Видео Object Oriented Programming 7 – Constructors канала Computer Science