Ladwa - OBJECT ORIENTED PROGRAMMING WITH JAVA

1. Emphasizes on the procedure rather than data.

1. Emphasizes on the data rather than the procedure.

1. Data is not secured.

1. Data is secured.

1. Uses a top-down approach.

1. Uses bottom-up approach.

1. It does not model real world entities.

1. It models real world entities.

1. Programs are decomposed into functions or procedures.

1. Programs are decomposed into objects.

Similarly, the solar system is a class whereas, an individual planet in a solar system is called an object.

Data encapsulation: the process of wrapping up data and functions into a single unit called class is called data encapsulation. Data encapsulation makes data hidden; data hiding is an act of insulating data from outside programs. The data is not accessible directly to the outside world, except for the functions defined inside the class definition. These function members provide an interface between the data and outside world to access the data out of class. Inheritance: it is a process of acquiring properties from an object of one class to properties of an object of another class. The class that inherits the properties to the other class is called base class or parent class or super class.

The class that inherits the properties from the other class is called derived class or child class or subclass. The programmers can add new features to the already existing class without modifying that class. This is achieved by deriving a new class from the already existing class. The derived class has its base class features, in addition to that it has its own features.