In object-oriented programming, what does encapsulation refer to?

Encapsulation in object-oriented programming is a fundamental concept that involves bundling the data (attributes) and the methods (functions) that operate on that data into a single unit, known as an object. This design allows for the data to be protected from outside interference and misuse, enabling a controlled access mechanism. Through encapsulation, the internal state of an object can only be changed using specific methods, which can enforce rules about how the data can be manipulated.

For example, consider a class representing a bank account. The balance of the account (data) and methods to deposit or withdraw funds (methods) are encapsulated together. The direct manipulation of the balance is restricted, and changes can only occur through the provided methods, ensuring that business rules (like not allowing a withdrawal that exceeds the balance) can be enforced.

This concept is essential for maintaining the integrity of data and enhances modularity in software design. It distinguishes the implementation details from the interface, allowing programmers to work with objects without needing to understand their inner workings, thereby promoting a high level of abstraction.

This makes encapsulation crucial for managing complexity, as it helps in creating well-defined interfaces and reduces interdependencies between different parts of a program, contributing to better software maintenance and evolution over time