Java Setter and Getter [closed]

Question

It is always recommended to use getter/setter for accessing private variables. Why would it not be a better idea to declare them as public and access them. Anyway we are accessing it using getter and setter?

Answer 1

Encapsulation.

Hiding internal state and requiring all interaction to be performed through an object's methods is known as data encapsulation — a fundamental principle of object-oriented programming.

See also:

• What Is an Object

Answer 2

@mre answer is excellent and your question is fundamental. To summarize : you put the fields of an object private to gain control over the way it will be used by other objects. Your object uses setter to:

• restrict and validate data passed to the setter
• hide its inner data structure (other object are interested by a service not how the service is built, this can also include optimisation)
• preserve its integrity in every state (changing other fields if required)

it will use getter to

• format data in output as desired by the client
• control a sequence of services (for instance it will provide data if and only if a connection has been established)

welcome in the wonderfull world of OO programming and the magics of structured programming.

Stéphane