Object-Oriented Programming

Object-Oriented Programming (OOP) is a software design paradigm that organizes code around objects rather than functions and logic. An object bundles state (data) with the behavior (methods) that operates on that state, letting developers model real-world things and their relationships directly in code. It has been one of the dominant ways to structure software for decades, underpinning languages like Java, C#, Python, and Ruby.

• Encapsulation - Data and the methods that act on it are packaged together, and internal details are hidden behind a public interface.
• Inheritance - New classes extend existing ones, reusing and specializing behavior without rewriting it.
• Polymorphism - Different objects can respond to the same call in their own way, so code can work against an interface rather than a concrete type.
• Abstraction - Complexity is exposed as simple, well-defined contracts that hide the messy implementation underneath.

OOP shows up in API work mostly as the mental model behind the systems an API fronts and the SDKs that consume it. Resource-oriented API design borrows directly from object thinking — a resource with its properties and the operations you can perform on it is not far from an object with its attributes and methods — and code-generated client libraries almost always render an API’s resources as classes. Where it gets awkward is when object hierarchies leak into the interface itself; a good API contract, like a good OpenAPI definition, abstracts the internal object model away so consumers depend on a stable interface rather than your class structure.