Need of object oriented programming
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Object oriented programming (OOP) addresses limitations of procedural programming by dividing programs into objects that encapsulate both data and behaviors. OOP supports features like inheritance, polymorphism, and abstraction. Inheritance allows new classes to inherit attributes and behaviors from parent classes, polymorphism allows the same message to be interpreted differently depending on the object receiving it, and abstraction focuses on essential characteristics without implementation details. These features help make programs more modular, reusable, and maintainable.
Need of object oriented programming
- 1. Need of Object Oriented Programming Amar Jukuntla
- 3. Procedure Oriented Programming Object Oriented Programming
- 4. Why Do We Need Object‐Oriented Programming? • Object Oriented Programming was developed because limitations were discovered in earlier approaches to programming. • To appreciate what OOP does, we need to understand what these limitations are and how they arose from traditional programming languages.
- 6. POP Vs. OOP Procedure Oriented Programming Object Oriented Programming • In OOP, program is divided into parts called objects. • OOP has access specifiers named Public, Private, Protected, etc. • OOP provides Data Hiding so provides more security. • In OOP, overloading is possible in the form of Function Overloading and Operator Overloading. • In OOP, data can not move easily from function to function, it can be kept public or private so we can control the access of data. • Example of OOP are : C++, JAVA, VB.NET, C#.NET. • In POP, program is divided into small parts called functions. • POP does not have any access specifier. • POP does not have any proper way for hiding data so it is less secure. • In POP, Overloading is not possible. • In POP, Most function uses Global data for sharing that can be accessed freely from function to function in the system. • Example of POP are : C, VB, FORTRAN, Pascal.
- 8. • Code Reuse and Recycling: Objects created for Object Oriented Programs can easily be reused in other programs. • Design Benefits: Large programs are very difficult to write. Object Oriented Programs force designers to go through an extensive planning phase, which makes for better designs with less flaws. In addition, once a program reaches a certain size, Object Oriented Programs are actually easier to program than non-Object Oriented ones. • Software Maintenance: Programs are not disposable. Legacy code must be dealt with on a daily basis, either to be improved upon (for a new version of an exist piece of software) or made to work with newer computers and software. An Object Oriented Program is much easier to modify and maintain than a non-Object Oriented Program. So although a lot of work is spent before the program is written, less work is needed to maintain it over time. • Simplicity
- 9. Binding Binding • Binding means link between procedure call and code to be executed. • When a method call is resolved at compile time, it is known as STATIC BINDING. • While if method invocation is resolved at runtime, it is known as DYNAMIC BINDING OR LATE BINDING.
- 10. Continue… Because of polymorphism, a reference variable of type Parent can hold an object of type Child, which extends Parent. Now if you call a virtual method (not private, final or static) on this object, then Compiler can not find actual method, because it could be the one, which is defined in Parent class, or the one which Child has overridden. This call can only be resolved at runtime, when actual object is available. That's why this is known as RUNTIME OR DYNAMIC BINDING. On the hand, private, static and final methods are resolved at compile time, because compiler knows that they can't be overridden and only possible methods are those, which are defined inside a class, whose reference variable is used to call this method. This is known as STATIC OR COMPILE TIME BINDING, all private, static and final methods are resolved using static binding.
- 11. Continue… This concept is also closely related to method overloading and method overriding. As dynamic binding happens when method overriding is possibility and overloaded method calls are resolved at compile time, because they are always defined in same class.
- 12. • Class • Class is a Blueprint for an Object. • Object • Object is instance of class or it is created from class. Attribute Behavior Name Walk Weight Run Height Talk Age Speak Gender Sleep P R O P E R T I E S M E T H O D S
- 13. Message Passing
- 14. Exception
- 15. OOP Features • Encapsulation • Inheritance • Polymorphism • Abstraction • Method overloading • Method overriding
- 16. OOP Features • Encapsulation • Encapsulation is the mechanism binds code and data together, and keeps both safe from outside interference and misuse. • Encapsulation is protective cover that prevents the code and data from being accessed by other code defined outside. • The process of wrapping up of data (properties) and behavior (methods) of an object into single unit. In plain English means to be enclosed in or as if in a capsule. • Advantages • The fields of a class can be made read-only or write-only. • A class can have total control over what is stored in its fields. • The user doesn’t know how the class stores data.
- 17. Continue… Class encapsulation { public void method1() { int i=0; //variable String Name=“Variable”; //variable } public void method2() { int i=0; //variable String Name=“Variable”; //variable } }
- 18. Continue… • Inheritance • Inheritance is the method creating the new class based on already existing class. • The new desired class is called subclass or child class. The existing class is called parent class or super class or base class. • Inheritance is the process by which one object acquires the properties of another object. • Example;
- 20. Continue… • Polymorphism • Ability to change form is known as Polymorphism. • Polymorphism means “many forms”. • Method overloading, method overriding, interfaces are the example of Polymorphism. • Example:
- 21. • Overloading • The same method name (method overloading) or operator symbol (operator overloading) can be used in different contents. • In method overloading, multiple methods having same name can appear in a class, but with different signature. • Java does not allow operator overloading yet + is overloaded for class string. The ‘+’ operator can be used for addition as well as string concatenation. • Example: • Add a1=new Add(); • Add a2=new Add(1,2); • Add a3=new Add(1,2,3);
- 22. Continue… • Overriding • Defining a method in subclass having the same name as a method in the parent class is known as Overriding.
- 23. Continue… • Abstraction • Abstraction specifies necessary and sufficient descriptions rather than implementation details. • Abstraction is an essential element of Object Oriented Programming. Through abstraction we can manage complexity. • Abstraction means hiding the unnecessary data from users. Abstraction defines only the essential characteristics of an object.
- 25. Summary of Object Oriented Programming Concepts • Everything is an Object. • Computation is performed by objects communicating with each other, requesting that other objects perform actions. • Each object has its own memory, which consist of other objects. • Every object is an Instance of a class. A class simply represents a grouping of similar objects, such as integers or lists. • The class is the responsible for behaviour associated with an object. That is, all objects that are instance of the same class can perform the same action. • Classes are organized into a singly rooted tree structure, called the Inheritance hierarchy.