Can you explain the meaning of the letter L in the SOLID principle?

The letter L in the SOLID principles stands for Liskov Substitution Principle. It states that objects of a subclass should be interchangeable with objects of the superclass without affecting the correctness of the program.

In simpler terms, if class B inherits from class A, then objects of class B should behave in a way that they can be used in place of objects of class A without unexpected errors or changes in logic.

This helps in creating class hierarchies where subclasses extend functionality without breaking existing code.