What is OOP?

What is OOP?

Object Oriented Programming (OOP) is a software development technique where a developer will create an abstraction (in code) of a real world object or concept. The belief is that if you can create a high enough fidelity model between the real world objects and the objects in your code, writing applications to automate the usage and automation of those objects will be easier. This approach has been mostly successful and is the most common software development paradigm that you will see in building Line of Business (LOB) applications.

When developing applications using OOP, you will define Classes that model real world objects. In your application these classes will be instantiated into Objects. In the course of the applications lifetime your code will call methods on these objects and potentially pass them to other methods as arguments. The interaction between classes is controlled be each classes public API, otherwise known as the collection of public methods and properties on the class. As we move into code samples in further posts you will see classes being created and methods on them being tested.

The terms “class” and “object” are NOT interchangeable. A Class is a definition of what an object should look like. It’s the blueprint you create by writing the C# or VB.NET that has the class’s member variable and methods. An Object is an instantiation of a Class. When you declare a variable of type class and either accept an instantiated object or you create an object using the “new” keyword, you get an Object based on the Class that was used to create the object.

OOP has three major tenets; Encapsulation, Inheritance and Polymorphism