Encapsulation and Access Modifiers

This lesson covers encapsulation -- one of the four pillars of Object-Oriented Programming -- and the use of access modifiers to control visibility of class members. This is a core topic in the OCR A-Level Computer Science (H446) specification.

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What is Encapsulation?

Encapsulation is the principle of bundling data (attributes) and the methods that operate on that data into a single unit (a class), while restricting direct access to the object's internal state. External code interacts with the object only through its public interface (methods), not by directly reading or modifying its attributes.

Why Encapsulation Matters

Benefit	Explanation
Data protection	Private attributes cannot be accidentally modified by external code.
Controlled access	Getters and setters allow validation before data is read or changed.
Reduced coupling	External code depends on the public interface, not the internal implementation.
Easier maintenance	Internal implementation can change without affecting code that uses the class.
Easier debugging	Bugs related to data can be traced to the class itself.