Grade 12 : Computer Science Chapter 5 (OOP)

UNIT 5: Object Oriented Programming

---

1. What are the programming methods or approaches of program development?

There are two approaches of program development:

1. Procedure Oriented Programming (POP) – a conventional programming method.

2. Object-Oriented Programming (OOP) – a modern programming approach.

3. 
   

---

2. What is Procedure Oriented Programming?

It is a conventional method of programming in which a program is divided into many small parts and combined together.

• In this approach, functions are created and data is not prioritized.

• Variables are created for data handling and can be global or local:

  • Local variable: Created inside sub-programs.

  • Global variable: Created in the main module and accessible from any module.

• Data alteration is very high in this method.

• 
  

---

3. What are the features of Procedure Oriented Programming?

• A large program is broken down into smaller programs or procedures.

• Focus is on functions rather than data.

• Variables are categorized as local and global.

• High possibility of data alteration (main disadvantage).

• Follows a top-down approach.

• 
  

---

4. What is Object Oriented Programming?

OOP is a modern programming approach where:

• Real-world entities are treated as objects.

• Objects are collected into classes, and classes may be controlled by superclasses.

• Inheritance allows changes in a superclass to be passed to its subclasses.

• Data is given high priority compared to functions, and data hiding reduces the risk of accidental alteration.

• 
  

---

5. What are the characteristics of OOP?

• Emphasis is on data.

• Programs are divided into objects.

• Functions and data are tied together in a single unit.

• Data hiding prevents accidental alteration.

• Follows a bottom-up approach.

• 
  

---

6. Differences between Procedure Oriented and Object Oriented Programming

---

7. Write short notes on the following:

a) Object
Entities in OOP are called objects (e.g., people, teachers, students, books, cars).

• Attributes: Characteristics like color, size, weight.

• Behavior/Functions: Actions like move, turn.

b) Class
A user-defined data type that defines the data types and functions of objects under it.

• Example: A class Vehicle can have objects like car, bus, truck.

c) Abstraction
Hiding internal details of an object and exposing only the interface.

• Increases data security and reduces complexity.

d) Encapsulation
Combining data and functions together in a single unit.

• Prevents unrelated functions from accessing unnecessary data.

e) Inheritance
Creating new classes (subclasses) based on an existing superclass.

• Enables code reuse and models real-world relationships.

f) Polymorphism
The ability to use the same operator or function in different ways.

• Example: + can be used for both arithmetic and string concatenation.

• 
  

---

8. What are the advantages and disadvantages of OOP?

Advantages:

• Code repetition is reduced (via inheritance).

• Data hiding ensures security.

• Existing classes can serve as libraries.

• Easier software development and maintenance.

• Models real-world systems effectively.

• Code reusability is improved.

• 
  

Disadvantages:

• High compiler and runtime overhead.

• Requires object-oriented thinking and software engineering expertise.

• Useful mainly for large and complex projects.

• 
  

---

Applications of OOP

1. Expert Systems

2. Artificial Intelligence (AI)

3. Management Information Systems (MIS)

4. Decision Support Systems

5. Computer-based Training & Education

6. Object-Oriented Databases

7. Computer Games

8. Mobile Applications

9. Internet-based Applications

10. User Interface Design

11. Security Systems