The Open/Closed principle says that we should strive to write code that doesn’t have to be changed every time the requirements change. Here's a simple example.
Out of the five SOLID principles the Open/Closed Principle is probably the one that I’ve had the hardest time understanding. However, a while ago though I found some code that I had written years ago that made me think to myself “Hey, this is clearly violating the Open Closed Principle!”.
