Slide 14.3: Abstraction (cont.): An example (cont.) Slide 14.5: Encapsulation (cont.): Get and set Home

Encapsulation

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Encapsulation is defined as the wrapping up of data under a single unit. It is the mechanism that binds together code and the data it manipulates. Other way to think about encapsulation is, it is a protective shield that prevents the data from being accessed by the code outside this shield.

• Technically in encapsulation, the variables or data of a class is hidden from any other class and can be accessed only through any member function of own class in which they are declared.


• As in encapsulation, the data in a class is hidden from other classes, so it is also known as data-hiding.


• Encapsulation can be achieved by declaring all the variables in the class as private and writing public methods in the class to set and get the values of variables.

Differences Between Abstraction and Encapsulation

• Abstraction hides complexity by giving a more abstract picture of a complex system. For example, a class Car would be made up of Engine and Steering objects, and many more components. To build the Car class, one does not need to know how the different components work internally, but only how to interface with them; e.g., send messages to them and receive messages from them.


• Encapsulation hides internal working so that you can change it later. For example, all implementations and declarations related to the car wrap in the single unit called class, like Car class.

In short, abstraction hides details at the design level, while encapsulation hides details at the implementation level.

Abstraction	Encapsulation
Abstraction is a general concept formed by extracting common features from specific examples or the act of withdrawing or removing something unnecessary.	Encapsulation is the mechanism that binds together code and the data it manipulates, and keeps both safe from outside interference and misuse.
You can use abstraction using interface and abstract class.	You can implement encapsulation using access modifiers (public, protected, and private).
Abstraction solves the problem in design level.	Encapsulation solves the problem in implementation level.
For simplicity, abstraction means hiding implementation using abstract class and interface.	For simplicity, encapsulation means hiding data using getters and setters.

Review: Abstraction and Encapsulation

Which statement is NOT true about abstraction and encapsulation?   Abstraction solves the problem in design level.   Encapsulation means hiding data using getters and setters.   Encapsulation solves the problem in implementation level.   You can implement abstraction using access modifiers (public, protected, and private).

Result:

Slide 14.3: Abstraction (cont.): An example (cont.) Slide 14.5: Encapsulation (cont.): Get and set Home

I was playing chess with my friend and he said,           “Let’s make this interesting.” So we stopped playing chess.           — Matt Kirshen