Fundamental Concepts of Object Oriented Programming

Summary

This video from Computer Science Lessons dives into the four fundamental concepts of Object-Oriented Programming (OOP): abstraction, encapsulation, inheritance, and polymorphism. It starts by defining an object as an entity of interest in software, which may not always be a physical item. The discussion moves to how classes form the template for creating objects in programming, emphasizing the importance of methods and properties. Encapsulation is highlighted as a means to hide an object's complexity, helping developers use objects without needing to understand their internal workings. The video also covers how inheritance allows classes to derive methods and properties from other classes, and how polymorphism enables these classes to use inherited methods in unique ways to suit specific needs.

Highlights

• Defining an object in OOP as anything of interest to the software. 🔍
• Classes act as blueprints for creating objects, including methods and properties. 📘
• Encapsulation hides an object's complexity, simplifying its use in programming. 🤫
• Inheritance lets a class derive methods and properties from another, building a hierarchy. 🔗
• Polymorphism allows different classes to implement inherited methods in distinct ways. 🔄

Key Takeaways

• Abstraction means simplifying reality to focus on relevant data and tasks for an application. ✨
• Encapsulation protects the data within an object, hiding its complexity from outside interference. 🛡️
• Inheritance creates a hierarchy of classes, enabling them to share methods and properties. 🌳
• Polymorphism lets different classes implement inherited methods in unique ways. 🎭
• Overall, understanding these concepts can help in efficient and effective OOP programming! 🚀

Overview

At the core of object-oriented programming (OOP) are four essential concepts: abstraction, encapsulation, inheritance, and polymorphism. It's all about understanding how objects, which can be anything of interest in your software application, come into play. A class acts as a blueprint for these objects, defining attributes and operations, which are better known as properties and methods. This helps simplify the complexity of the real world, focusing on only what's relevant for the application.

Encapsulation in OOP refers to the concept of binding data and the functions that manipulate that data together, shielding their complexity from the programmers. This means developers can use and build upon an object without needing deep insights into how it works internally. It's a powerful way to ensure the integrity and security of an object's data and operations, often inspired by more experienced programmers in big software projects.

Inheritance and polymorphism are powerful features of OOP, fueling reusability and flexibility. Inheritance allows new classes to borrow methods and properties from existing ones, creating a hierarchy that mirrors real-world relationships, like an employee deriving attributes from a person. Meanwhile, polymorphism provides the ability to override inherited behavior, enabling classes to uniquely adapt functionalities to meet specific needs efficiently.

Chapters

• 00:00 - 01:00: Introduction to Object-Oriented Programming (OOP) The chapter introduces the concept of Object-Oriented Programming (OOP), which is centered around four main principles: abstraction, encapsulation, inheritance, and polymorphism. It starts with the definition of an object, describing it as an entity that can represent real-world things such as a car, a boat, or a book.
• 01:00 - 03:50: Abstraction This chapter delves into the concept of 'Abstraction' in object-oriented programming (OOP). It explains that objects, in this context, might not always be physical entities but can also be intangible items such as appointments, reservations, or accounts. These objects or entities are what the software application needs to store and process data about, thus forming the core of OOP.
• 03:50 - 07:00: Creating Objects and Classes This chapter introduces the concept of abstraction in object-oriented programming. It explains that abstraction is the process of simplifying reality by focusing only on the essential characteristics relevant to the context at hand. For instance, when designing an application to process data about a person, one would not need to capture every detail about that person but only the necessary information.
• 07:00 - 10:00: Encapsulation This chapter introduces the concept of encapsulation in programming. It explains that encapsulation involves bundling the data with the methods that operate on the data. The idea is to restrict access to certain components and to prevent the accidental modification of data. To create objects programmatically, one needs a class, which serves as a template for creating objects. A class defines the properties (attributes) and behaviors (operations or methods) of the object, making encapsulation a key principle in object-oriented programming.
• 10:00 - 12:00: Inheritance In "Inheritance", the chapter delves into the structure and functionality of classes, focusing on how properties within a class are defined either as public variables or through property procedures. It elaborates on operations, or methods, which represent the actions that can be performed by the object. These methods are crucial as they define the behavior of objects and are implemented as either procedures or functions. The chapter emphasizes understanding a class as a blueprint for creating objects, outlining the fundamental concept of inheritance in object-oriented programming.
• 12:00 - 15:00: Polymorphism This chapter discusses the concept of polymorphism in programming. Polymorphism allows objects to be treated as instances of their parent class, enabling a single function or method to work on different types of objects more flexibly. The analogy of a pastry cutter is used to explain how a class can be used to create multiple objects of the same type. Each object is an instance of a class, with the process of creating an object known as instantiation. After instantiation, properties of these objects can be assigned values.

Fundamental Concepts of Object Oriented Programming Transcription

• 00:00 - 00:30 the four fundamental concepts of object-oriented programming are abstraction encapsulation inheritance and polymorphism before considering what they mean first consider what is an object an object is a thing from the real world it could be a car a boat or a book
• 00:30 - 01:00 but it might not be something physical that you can touch it could be a dental appointment a seat reservation for the cinema or a bank account in the realm of object object-oriented programming an object is anything of interest to the software application that you're building it's anything that you want to store and process data about another name for an object is an entity
• 01:00 - 01:30 this leads us to the first fundamental concept of object-oriented programming namely abstraction abstraction means to simplify reality for example a person is an object but if you were designing a new application to process data about a person it's unlikely that you'd be interested in everything there is to know about a person rather you would only concern yourself
• 01:30 - 02:00 with the data that are relevant and the tasks that you want to perform with those data to create objects programmatically you need a class a class is a template for creating objects a class is code written by a programmer to define the attributes and the operations of an object attributes describe the object they're sometimes referred to as fields because they contain data most programmers know them as properties
• 02:00 - 02:30 properties are coded within the class either as public variables or as property procedures operations are actions that can be done to or performed by the object they're sometimes referred to as behaviors but more commonly they're known as methods methods are programs within the class that are coded either as procedures or functions a class is a template for creating objects and it's often
• 02:30 - 03:00 compared with a pastry cutter because once it's been written it can be used to create many objects of the same type in fact a class is sometimes referred to as a type each object is an instance of a class in the computer's memory creating an object from a class is therefore known as instantiation once these objects have been created their properties can be assigned values
• 03:00 - 03:30 making each object of the same type a unique entity each property is defined in the class by a property procedure which may include code to validate a property value while it's being assigned this helps to ensure the integrity of the data contained within the object the property values that have been assigned to an object are collectively known as the state of the object it's also possible to assign values to
• 03:30 - 04:00 properties while an object is being instantiated by means of a special method called new this method is known as the constructor the second fundamental concept of object-oriented programming is encapsulation this means to hide the complexity of the inner workings of an object from the programs and the programmers that make use of it it's often referred
• 04:00 - 04:30 to as information hiding because the data contained within an object and the functions that manipulate the data are bound together and therefore safe from outside interference in some big software development projects it's common for more experienced programmers to write the classes that will be used by the junior programmers a class might be made available in the form of a class library indeed some software development
• 04:30 - 05:00 companies specialise in developing new classes to be used by other software developers compiled class libraries protect their intellectual property to write code that will create an object from a class then set its properties and call its methods it's not necessary to understand the inner workings of the class all the programmer needs to know is the name of the class
• 05:00 - 05:30 the properties and methods available and any data that need to be supplied when they're called in other words all our programmer really needs to know about is the interface of the class the implementation code of those properties and methods can remain a mystery this greatly simplifies the use of objects and helps to ensure that the data and operations encapsulated within are safe the third fundamental concept of
• 05:30 - 06:00 object-oriented programming is inheritance this means that a class can derive its methods and properties from another class inheritance can result in a hierarchy of classes for example this person class defines the methods and properties of a person object an employee in a business is also a person so through inheritance an employee class derives the methods and properties of
• 06:00 - 06:30 the person class an employee is a type of person a customer of the business is also a person so through inheritance a customer class also derives the methods and properties of the person class a customer is a type of person an employee class can have some extra properties and methods of its own it can extend the person class
• 06:30 - 07:00 and so can a customer but it need not stop there a programmer is a type of employee and so is a manager and a cleaner inheritance defines type of relationships the class at the start of the inheritance hierarchy is called the base class any class that derives from another class
• 07:00 - 07:30 is called a sub class any class that is derived from is called a superclass the final fundamental concept of object-oriented programming is polymorphism polymorphism means that a class can implement an inherited method in its own way the person class at the base of this hierarchy has a method which will save details of
• 07:30 - 08:00 any object created from the person class perhaps to a database thanks to inheritance all of the classes in this hierarchy do exactly the same thing but it may be necessary for a customer's details to be saved differently perhaps to a different database polymorphism allows for this the customer class can override the workings of any method or
• 08:00 - 08:30 property that it inherits with a new version of its own different forms of the same type of object with the same interface can behave in different ways polymorphism literally means many forms to recap the fundamental concepts of object-oriented programming abstraction means to simplify reality and focus only on the data and processes that are relevant to the application
• 08:30 - 09:00 being built encapsulation means that data and the programs that manipulate those data are bound together and their complexity is hidden inheritance means that a class can derive its methods and properties from another class this might result in an extensive hierarchy of superclasses and subclasses polymorphism means that different
• 09:00 - 09:30 subclasses of the same superclass which therefore share the same interface can implement those interfaces in their own ways by overriding the code of the methods they inherit