Object Oriented Programming

KS3 Computer Science

11-14 Years Old

48 modules covering EVERY Computer Science topic needed for KS3 level.

GCSE Computer Science

14-16 Years Old

45 modules covering EVERY Computer Science topic needed for GCSE level.

A-Level Computer Science

16-18 Years Old

66 modules covering EVERY Computer Science topic needed for A-Level.

GCSE Programming Resources (14-16 years)

  • An editable PowerPoint lesson presentation
  • Editable revision handouts
  • A glossary which covers the key terminologies of the module
  • Topic mindmaps for visualising the key concepts
  • Printable flashcards to help students engage active recall and confidence-based repetition
  • A quiz with accompanying answer key to test knowledge and understanding of the module

A-Level Problem solving and programming (16-18 years)

  • An editable PowerPoint lesson presentation
  • Editable revision handouts
  • A glossary which covers the key terminologies of the module
  • Topic mindmaps for visualising the key concepts
  • Printable flashcards to help students engage active recall and confidence-based repetition
  • A quiz with accompanying answer key to test knowledge and understanding of the module


Object- orientated programming (oop) reflects an effort the way we all think and interact with the real world more closely with programs. In the previous programming types, a programme writer was presented with a computational activity to solve the problem. software design then consists of finding a set of instructions that will perform the assignment. In any case, rather than errands, we discover antiquities at the focal point of object- orientated programming: elements that have practices, hold data, and that tin speak with one another. software design requires the creation of a collection of artefacts which model the issue imminent. in the programs, software instances may represent actual or abstract entities in the problem area. This is meant to make the software design more intuitive and therefore easier to get accurate and easier to comprehend. one of many software design paradigms is object- orientated programming.

Object Oriented Programming

object-orientation is a collection of techniques that enable developers to construct secure, accessible, sustainable, well-documented, recyclable software systems that meet their users ‘ needs. it is stated that object-orientation offers new mind resources for software developers to use in solving a wide range of issues. a new view of computation is given by object-orientation. In solving a problem, a software is considered as a group of stuff that communicate with each other by parameters.

 The following object- orientated principles are supported by oop:

  • classes
  • objects
  • inheritance
  • abstraction
  • polymorphism and virtual function
  • file handling

Our first conceptual image of software design directed towards objects: oop provides the ability of programming based on objects. object is an entity containing data and functions.

List of Languages that use OOP:

  • Python
  • C++
  • Eiffel
  • CLOS
  • Smart Talk
  • Visual Basic .Net
  • JAVA
  • Objective C
  • Curl
  • Ruby
  • Delphi

Importance of OOP

It is the logic that one uses in everyday life. we ponder things as objects with characteristics and manners, of course, and that defines how we communicate with them. in the abstract, it interacts, and this is why oop will improve speed and efficiency.


You use a remote control if you want to shift the tv channel from your place. that remote control is an entity concealed inside of it with a variety of attributes and behaviors. you also recognize and believe that pressing a button would execute that specific function without thoughtful of these secret attributes the microchips, wiring, etc. in the abstract, you’ve communicated with the remote, missing the steps that the remote was programmed to take. The emphasis is on how the objects act, not the code needed to state them how to act, which is the beauty of oop.

Object-oriented programming & the creation of back-ends

In terms of how a site is designed, what is object- orientated programming? most modern server-side scripting languages, which are used by back-end developers to write software and database technology, are specified by oop. This server-side innovation in the background tells a site or web application the proper behavior, and furthermore gives the foundation to a website to associate with its information base. The framework is the means by which information is provided and put away, making it the mind of a site successfully. furthermore, that is the place it becomes possibly the most important factor with object- orientated logic. on the off chance that the mind of a site utilizes object- orientated reasoning, it is intended to consider information objects. it influences how a site is planned from the beginning, how information is masterminded, how the site will be made and looked after later, and that’s only the tip of the iceberg.

Object-oriented technology benefits include:

  1. Computer  interface ease
  2. Productivity  within
  3. Easy  checking, debugging and servicing
  4. Reusable,  it is
  5. Thanks  to the inheritance approach of oop, data analysis tin be done in less time with precise code or bug free environment as compared to pop.
  6. Hiding  & abstraction, data is benign and stable, with less data fraud.
  7. It’s shareable (classes tin be reused and spread to other networks)

The OOP building blocks

Objects are key to OOP, but they aren’t the only element that comprises OOP. There are some other building slabs as well and how they function together in order to construct the code that hosts deploys data into a functional web application from a database.

1)     Objects:

These play the most important role. It represents an entity in the real world and is identified by its name. It consists of properties and functions. E.g. Car is a mixture of several attributes, of a complex object. In order to know how to deal with it, we don’t want to comprehend its inner workings, i.e. How the engine works, how the car starts, or the working of the fuel carbonator? Via object-oriented logic, the action of the car has been made easy for us: we place the car key in the ignition, and the car starts and we can go where we want to go. Qualities which make this happen are a “box” that we do not need to break down in order to comprehend all the components, circuitry, and engineering of the vehicle. A more specific example is for instance, in a subclass of “hybrid cars, ” a Prius car is an entity in the class of “cars.” Its characteristics contain everything from how many doors the car has and how it gets charged. Via its actions it drives, it is identical to other vehicles, but its characteristics differentiate it from others. Apply this to software development, enabling developers to collapse large complex projects into sorted objects, programme them to have features and performances, then effectively set them away and concentrate on development of how the objects communicate, an advanced level of thought that makes code writing a bit less linear and more effective.

2)   Classes:

It is a drawing for object applications. It is used for the development or distribution of creating objects. A class defines the state of its instances by requiring the object needed for each object’s state to be contained. The class defines the actions of objects by declaring the instance methods required to work on the object status and by providing implementations.


A group of objects with the same functionality and features in known as class. For building objects, a class is a kind of workshop. The non-static class components define or label the variables and methods of the objects. It will hold them. You can create multiple instances from the class after you’ve developed the class. All objects that are generated by the class will have the same features. Instances are formed and demolished as we run a programme, and if they are created using the same class, there may be several objects of the same structure. Using the previous example, 4 wheels, a machine, a frame, handbrakes, etc., a class determines the concept of a vehicle. It requires all objects in the class to pass certain specified criteria. On a basic level, all kinds of cars act relatively the same, but their features and approach make them distinct.               

3)   Inheritance:

A programming method that is used to reuse a prevailing class to build a new class is known as inheritance This is an integral aspect of OOP. The new class inherits all the behavior of the original class. Let’s say, splitting a bike into subclasses (bike sports bike Suzuki sports bike) would make it likely without starting from scratch and to layer in more features. Before Inheritance Rather than making new classes from old classes, you should only copy the source code for the old class inheritance and change it. So that it does what you want, exactly. But this leads to difficulties. You could copy the code and modify it if you have the source code for a class. It’s about doing what you want. That was what was prior to object-oriented programming. But with this, there are at least two problems:

  • Staying organized is challenging. Tell that you have several dozen classes already, and that, based on the original ones, you need extra classes. Often, say, say, based on the new classes, you would need many classes. You’re going to end up with hundreds of source files, many of which are copies of other source files. In different respects, they have been altered. Without thorough training, you could end up with a buggy mess that is unorganized, inconsistent.
  • You need the original code to review. Say you’re having a complicated lesson, it essentially does what you want, but you need a tiny adjustment. If you edit the source code, you risk breaking something even if you make a minor adjustment. Then you must review the original code to make sure your changes are accepted. And maybe that’s not easy.

Access Specifiers in Inheritance:

Things become a little more complicated when dealing with inherited groups. OOP has three access specifiers that we have yet to address because these are beneficial in this sense. 

Public mode:

It allows the user to access the class member within the class and external class as well. The member declared with public access specifier can be assessed from anywhere in the programme.

Protected mode:

It lets the member access the class to which the member belongs, mates, and classes derived. Protected participants are not, however, available from outside the class. It is the least popular form of inheritance. Except in very rare situations, it is almost never used. The public and protected members become privileged with protected inheritance, and private members remain unavailable. 

Private mode:

When a subclass is resulting from a Private Base Class. In the resultant class, all public representatives and covered representatives of    the base class would then become private.


Single Inheritance:

 A type of inheritance where a child class is a derivative of a single super class. In other terms, only one base class inherits one sub class.

Object Oriented Programming: Single inheritance.

Multiple Inheritance:

Multiple Inheritance is wherever more than one class will accede to a class. In this type of inheritance, the derived class features the members of all the base classes.

Object Oriented Programming Image 1

Multilevel Inheritance:

 In this type of inheritance the members of the base class are inherited to the child class and the members of the child class are then inherited to the grandchild class. In this way the members of both the classes are then gathered in the grandchild class.

Object Oriented Programming Image 2

Hierarchical Inheritance:

 Multiple subclasses are inherited from a single class in this form of inheritance. That is, from a single class, more than one resulting class is being generated.

Object Oriented Programming Image 3

Hybrid (Virtual) Inheritance:

By incorporating more than one form of inheritance, Hybrid Inheritance is introduced.The hybrid / virtual inheritance is shown below:

Object Oriented Programming Image 4

4)    Abstraction and Encapsulation:

This explains how qualities, including their data, are contained and concealed within an entity. Objects are intended to disclose only the data required, enabling the package (programme) to communicate at a higher level with the object. It’s defense and simplicity of equal parts. In the case of car components, objects are less likely to get broken by securely loading them inside the frame of an accumulated car, and users can communicate with the vast image: pressing the accelerator means moving, no questions asked. Encapsulation is called the packaging of an entity’s variables in the safe keeping of his techniques. A neat software package is an encapsulation of associated variables and methods. A basic but powerful concept that offers software developers two advantages:


You can write and maintain the base code for an object. For other objects, independently of the base code. An instance can be a part of the method, quickly moved around. You can deliver your bicycle to someone, and it’ll do its job anyway.


An instance contains a public border which can be accessed by other objects. Using it to connect. The object should retain private data. The object should retain private data. Procedures which may be up to date at any time without influencing, in addition, structured instances.

5)   Polymorphism:

Depending on the situation, instances may assume more than one type. For any implementation of that entity, the programme can reuse the code without writing it over and over again. In Object Oriented Programming (OOPS) languages, two main types of polymorphisms exist. They are Static Binding and Dynamic Binding (Runtime Polymorphism) (Compile time Polymorphism). The Dynamic Polymorphism example would be method overriding, and the Static Polymorphism example would be method overloading.

Compile Time Polymorphism:

In Object Oriented Programming languages, one can achieve the state of static polymorphism by using the overloading process. This method would allow different methods to be implemented by the programmer. They could use the same names, but they have different parameters. An instance of Static Polymorphism is process overloading. For static polymorphism, there are certain conditions which are necessary. There are in terms of forms, all parameters should be different. The parameter order would have to be different. It will have to be different from the other method in the number of parameters of one method. The language compiler can distinguish different methods during the run time by defining the signatures of these methods. First, the compiler will define the signature of the method and then determine the method when compiling the programme for a particular method call. The execution time for Polymorphism Compile Time is much faster, but this approach is not very versatile.

Runtime Polymorphism:

This procedure is also referred to as the Dynamic dispatch system. A call to a single overridden method is solved during the programme’s runtime under this procedure. The prime example of Runtime Polymorphism is process overriding. The call is not solved by the compiler in this process. Overriding is accomplished by virtual functions and pointers. The Overriding Method is the mechanism by which a single method is declared in a sub-class present in a parent class. The child class will acquire a method for implementation through this process. The parent class of the child class is used to provide this process. This polymorphism method is slow, but it is more versatile than static polymorphism. The key benefit of Runtime Polymorphism is the right of the class to give another inherited method its own specification. It is possible to pass the implementation of one method to another method without altering or changing the parent class object codes. 


Procedural programming (languages such as ColdFusion) is code that is broken into “parts, ” an unlike way of being rational that is more linear about how code interacts with data. Procedures, like small machines that collect information, process it, then produce output, are usable bits of code that communicate with and modify data. However, with OOP, inside the object, qualities and procedures are banded together. This eliminates the need for OOP, which is a crucial difference between the two methods, for any shared or global data. Instead of thinking about the issue you are trying to solve, conventional procedural languages such as C and Pascal need you to think with respect to the machine. In the world of programme design, both POP and OOP are such languages and are commonly used in application development. Both languages have different methods on the basis of the essence of the creation of the text, depending on which both are distinguished from one another. The major differences b/w POP and OOP are as follows:                            

1DefinitionIt generates models based on the environment of the real-world using classes and objects. It makes it informal to manage and change prevailing code in OOPs as new instances are generated that inherit existing characteristics.Procedural Oriented Programming, on the other hand, follows a step-by-step approach through a sequence of instructions to collapse a task into a series of variables and procedures (or sub procedures). Each phase is done in a structured way so that a machine can comprehend what is to be done.
2ApproachThe definition of objects and classes is implemented in OOPs and the software is then split into small portions called objects that are class instances.On the other hand, the core program is split into tiny sections depending on the roles and viewed as a separate program for each tiny program.
3Access ModifiersAccess modifiers such as Private, Protected and Public are used to assist in Inheritance.In POP, no such modifiers are enforced.
4SecurityData hiding is possible due to abstraction in OOPs and therefore it is more reliable.POP is less secure.
5ComplexityOOPs are less complex because of the modularity of their programs, so new data structures can be simply generated from prevailing objects, making it easier to change object-oriented programs.There’s no quick method for inserting data in POP, on the other hand, at least not without checking the entire software.

Advantages and Disadvantages

Instead of the reasoning needed to exploit them, OOP focuses on the thing’s developers want to exploit. For programmes that are broad, complex, and actively modified or managed, this approach to programming is well-suited. The arrangement of an OOP also makes the approach useful for the creation of partnerships, where projects are divided into classes. OOP’s additional advantages include reusability of code, scalability, and effectiveness. Developers can continue to implement the OOP concepts even while using micro services.


  •  OOP provides modular structure which makes it easy to define abstract data types
  •  New instances can be created with minor changes to the prevailing ones, With OOP it is quite a simple task to maintain and modify the existing code.
  • For code libraries, a good platform is provided by OOP where software components can be easily modified and altered by the programmer. For the development of GUI, this is mainly helpful.
  • The message passing technique makes the definition of the interface with the external system much easier for communication between objects.


  • Compiler and overhead for runtime. The object-oriented software needed higher overhead processing demands for more resources.
  • The natural situation of an instance is in RAM as a dynamic unit, but in files or databases, conventional data storage. Re-orientation of object-oriented thought for software developers.
  • It includes a master’s degree in software engineering and programming.
  •  Benefits when handling massive software projects only in the long term.
  • It can be hard to track & debug the message that passes through several objects in a complex application.


  1. Eck DJ, Kjell BP, Pillay AW. Object-Oriented Programming. School of Computer Science, University of KwaZulu-Natal. 2007;57.
  2. https://www.upwork.com/hire/oop-freelancers/
  3. https://www.tutorialspoint.com/differences-between-procedural-and-object-oriented-programming
  4. https://www.geeksforgeeks.org/inheritance-in-c/
  5. https://www.learncpp.com/cpp-tutorial/115-inheritance-and-access-specifiers/
  6. https://en.wikipedia.org/wiki/Object-oriented_programming
  7. https://www.besanttechnologies.com/polymorphism-in-oops#:~:text=There%20are%20two%20major%20types,the%20example%20of%20Static%20Polymorphism