Inheritance (OOP programming)

Inheritance facilitates an “is-a” relationship between classes. For example, a ‘Dog’ is a type of ‘Animal’. In this scenario, ‘Animal’ would be the superclass, containing general attributes and methods like ‘age’ and ‘eat()’. The ‘Dog’ class would be the subclass, inheriting these properties and adding its own specific ones, like ‘breed’ and ‘bark()’. This avoids code duplication, as the common logic is defined once in the superclass and reused by all its subclasses. Changes made to the superclass are automatically propagated to all subclasses, simplifying maintenance.

There are different types of inheritance, including single inheritance (a class inherits from only one superclass), multiple inheritance (a class inherits from more than one superclass), and multilevel inheritance (a class inherits from another class which itself is a subclass). While powerful, inheritance can also introduce complexity and tight coupling between superclasses and subclasses. Overuse can lead to deep and convoluted hierarchies that are difficult to understand and maintain. Modern design often favors composition over inheritance, where an object contains an instance of another object to achieve code reuse, representing a “has-a” relationship.