The Open/Closed Principle (OCP) concept in software development

The Open/Closed Principle (OCP) is a fundamental concept in software development, particularly in object-oriented programming. It states that software entities (classes, modules, functions, etc.) should be open for extension but closed for modification. In simpler terms, this means that you should be able to add new functionality to a system without altering its existing code.

Let's break it down with a simple example in C#:

Suppose we have a simple application that calculates the area of different shapes like squares, rectangles, and circles. Initially, you might implement it like this:

This implementation violates the Open/Closed Principle because every time you add a new shape, you have to modify the CalculateArea method to handle the new shape.

To adhere to the Open/Closed Principle, you can use inheritance and polymorphism:

Now, whenever you want to add a new shape, you simply create a new class that inherits from Shape and implements the CalculateArea method without modifying existing code. This approach makes your code more flexible, easier to maintain, and less prone to introducing bugs when extending its functionality.