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Definition

                    The wrapping up of data members and member methods together into a single unit is called encapsulation.



              Example of encapsulation using class is as follows:


                                   class encapsulation_example                        Class
                                      {
                                           int a;
                                                                                      Data Members
                                           String n;
                                           void input(int a1, String n1)
                                           {
                                               a=a1;
                                               n=n1;
                                           }                                          Member Methods
                                           void display()
                                           {
                                               System.out.println(a);
                                               System.out.println(n);
                                           }
                                       }
              Both data members and member methods are enclosed within the braces of the class encapsulation example.

              3.2.2 Data Abstraction
              The  word  – ‘abstract’ means existing  in  thought as an  idea  but  does
              not have a tangible existence. An object in OOP language provides an
              abstraction that hides the internal implementation details. For example,
              while travelling in a car as a passenger, you think only of reaching the
              destination. But you never think of how the driver is driving the car by
              pressing the clutch, brake, and accelerator as and when required. Similarly,
              a driver, also only concerned with the steering wheel, accelerator, clutch,
              and brake. But he is least interested in how they execute their functions.
              In object-oriented programming, the key purpose of abstraction is to hide the details that are not required by the
              users. Abstraction is like a query passed to a database that extracts the required data only leaving the rest. The main
              purpose is to reduce the programming complexity. It is one of the most important concepts of OOPs.

                                                             Definition

                    Data abstraction is the property by which the essential features of a class are represented without knowing the
                    background details that how they are actually executing, i.e., non-essential units are hidden from the user.



              3.2.3 Inheritance
              The procedure of creating a new class with the help of a class already created       Vehicle
              by using its properties and functionality is said to be inheritance.

              It is one of the important pillars of object-oriented programming.                         Human-Powered
                                                                                       Motor Driven
              In the real world, a child inherits the properties (both materialistic and                    Vehicle
              non-materialistic)  of  his  parents,  who  have  inherited  them  from  their
              parents.                                                                     Car               Cycle


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