Encapsulation In OOPs

Encapsulation:

Encapsulation in Java is a process of wrapping code and data together into a single unit.  The best way to understand encapsulation is to look at the example of a medical capsule, where the drug is always safe inside the capsule. Similarly, through encapsulation the methods and variables of a class are well hidden and safe.

We can achieve encapsulation in Java by:

• Declaring the variables of a class as private.
• Providing public setter and getter methods to modify and view the variables values.

Often encapsulation is misunderstood with Abstraction.

• Encapsulation is more about "How" to achieve a functionality.
• Abstraction is more about "What" a class can do.

A simple example to understand this difference is a mobile phone. Where the complex logic in the circuit board is encapsulated in a touch screen, and the interface is provided to abstract it out.

Simple Java program to demonstrate encapsulation:

Advantages of Encapsulation:

• The user will have no idea about the inner implementation of the class.
• We can make the variables of the class as read-only or write-only depending on our requirement.
• Encapsulation also improves re-usability and is easy to change with new requirements.
• Encapsulated code is easy to test for unit testing.