Question

What are the differences between information hiding and encapsulation?

I have read that encapsulation means bundling data and the procedures that should operate on them together. If that is so, does the following class achieve encapsulation?

class IsThisEncapsulation {
    public int age;

    public int getAge() {
        return this.age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

Now would declaring the data attribute age private achieve information hiding?

Answer 1

Well I know that making fields private and then making setter and getter of the fields is encapsulation. However, does encapsulation mean just this?

—> Encapsulation is an OOP concept where object state(class fields) and it’s behaviour(methods) is wrapped together. Java provides encapsulation using class.

Information Hiding:

–> mechanism for restricting access to some of the object’s components. Your above example is the case of Information Hiding if you make age private.

---

Initially, Information/Data Hiding was considered the part of Encapsulation, and the definitions of Encapsulation would be as:

• A language mechanism for restricting access to some of the object’s components.
• A language construct that facilitates the bundling of data with the methods (or other functions) operating on that data.

the second definition is motivated by the fact that in many OOP languages hiding of components is not automatic or can be overridden; thus, information hiding is defined as a separate notion by those who prefer the second definition.

Reference: wikipage