OOPS Questions - Encapsulation and Abstraction in Simple Terms with Example
Encapsulation
Encapsulation means to encapsulate or put
everything into one thing and provide others to use it.
Wrapping up data member and method together
into a single unit (i.e. Class) is called Encapsulation.
Encapsulation means hiding the internal
details of an object, i.e. how an object does something.
Abstraction
Abstraction is a process to
abstract or hide the functionality and provide users or other programmer which
are necessary,
Abstraction
is "To represent the essential feature without representing the back
ground details.
Like for the method
Console.WriteLine(), no
one knows what actually is happening behind the function calling. We are just
using it by calling and passing the arguments. This is the thing called
Abstraction.
Example
Let's
assume you have to create a method to insert user’s data and pass it to other
developers to use. So first, create a class and add a method to insert the data
into database with validation.
There
will be three fields:
1. Name
2. Email
3. Phone number
Before insert into DB We will validate it.
First,
create a class with all methods:
class User
{
public bool AddUser(string name, string email, string phone)
{
if (ValidateUser(name, email, phone))
{
if (AddtoDb(name, email, phone) > 0)
{
return true;
}
}
return false;
}
private bool
ValidateUser(string name, string email, string phone)
{
// do your validation
return true;
}
private int AddtoDb(string name, string email, string phone)
{
// Write the Db code to insert the data
return 1;
}
}
As
you can see, there are three methods that are written in this User class.
·
AddUser: To call from outside the class. That is why
the access modifier is public.
·
validateUser: To validate the user's details. Can't access
from outside the class. It's private.
·
AddtoDb: To insert data into database table and again
it is private, can't access from outside the class.
Now
another user will just call AddUser method with
parameters. And that user has no idea what is actually happening inside the
method
To
call the AddUser method, do as follows:
class Program
{
static void Main(string[] args)
{
User objUser = new User();
bool f = objUser.AddUser("John", "john@abc.com", "34354543455");
}
}
Now
come back to the main discussion.
Here,
we are hiding the procedure of adding data into database from other users, this
is Abstraction. And putting all the three methods into one User class and providing other users to use
it, that is called Encapsulation.
So
procedure hiding is Abstraction and putting every necessary thing into one is
Encapsulation.
