What are the pillars of OOP in PHP?

The pillars of object-oriented programming (OOP) in PHP, as in most other object-oriented languages, are commonly referred to as the four pillars of OOP. These pillars represent the fundamental principles of OOP and help guide the design and implementation of object-oriented systems. The four pillars are:


Encapsulation is the principle of bundling data and the methods that operate on that data into a single unit called an object. It allows you to hide the internal state of an object and control access to it through public, private, and protected visibility modifiers. Encapsulation helps in organizing and structuring code, promoting information hiding, and providing a clear interface for interacting with objects.


Inheritance is the principle that allows you to create new classes based on existing classes, inheriting their properties and methods. In PHP, you can achieve inheritance using the extends keyword. Inheritance promotes code reuse, enables specialization and generalization, and establishes a hierarchical relationship among classes.


Polymorphism is the principle that allows objects of different classes to be treated as objects of a common parent class. It enables objects to take on multiple forms or behaviors depending on the context. Polymorphism is achieved through method overriding and method overloading. It promotes flexibility, modularity, and extensibility in your code by allowing objects to be used interchangeably.


Abstraction is the principle of simplifying complex systems by providing a simplified representation or interface. It involves the use of abstract classes, interfaces, and abstract methods to define a common structure and behavior for a group of related classes. Abstraction helps in managing complexity, providing a level of indirection, and promoting code reusability.

By adhering to these four pillars of OOP, you can design and develop well-structured, modular, and maintainable PHP code that exhibits characteristics such as encapsulation, modularity, flexibility, and code reusability. These principles form the foundation of object-oriented design and programming and are essential for building robust and scalable software systems.