Object oriented concepts with java
- 1. Object Oriented Concepts With JAVA Mehta Ishani 2nd M.E.(C.S.E)
- 2. Why OOP? • Traditional Procedural-Oriented languages – difficult to copy a function from one program and reuse in another program because the the function is reference the headers, global variables and other functions. (i.e. not well-encapsulated as a self-contained reusable unit.) – not suitable of high-level abstraction for solving real life problems.
- 3. Why OOP? • Object-oriented programming (OOP) languages – class, which encapsulates both the static attributes and dynamic behaviors (i.e. well- encapsulated, easier to reuse) – permit higher level of abstraction for solving real-life problems
- 4. Benefits of OOP • Ease in software design • Ease in software maintenance • Reusable software
- 5. What is JAVA? • programming language expressly designed for use in the distributed environment of the Internet • Simple, Secure, Robust, Complete Object Oriented and Platform Independent High level Language. • It is portable and Multi-thread technology gives High performance.
- 6. JAVA Hardware Platform Java Platform Software (OS) Platform Operates and Controls H/W Environment for Java Development JVM API
- 8. JAVA Java Program Virtual Machine Source code Bytecode Java Compiler Process of Compilation: Java Interpreter Virtual Machine Real MachineBytecode
- 9. Object • real word entity that has state and behavior • contains data (instance variables) representing its state, and instance methods, which are the things it can do. • instance of a class
- 10. Class • Collection of objects • template, blueprint or contract that defines what an object’s data fields and methods will be.
- 11. Abstraction • Hiding internal details and showing functionality • In java, we use abstract class and interface to achieve abstraction.
- 12. Encapsulation • Binding (or wrapping) code and data together into a single unit • A java class • Java bean
- 13. Inheritance • When one object acquires all the properties and behaviors of parent object • provides code reusability. • Used to achieve runtime polymorphism.
- 14. Inheritance A B C A B C A-1 A-2 B-1 B-2 AB Multi-level Inheritance Multiple Inheritance Multiple Multi-level Inheritance Types of Inheritance:
- 15. Ploymorphism • "Poly" means "many" and "morph" means "form". • When one task is performed by different ways
- 16. Polymorphism • same word or symbol to be interpreted correctly in different situations based on the context • There are two types of polymorphism : 1.Compile-time polymorphism (Method Overloading/Static) 2.Runtime Polymorphism (Method Overriding/Dynamic)
- 17. Ploymorphism Method Overloading: having multiple methods with same name but with different signature (number, type and order of parameters). Method Overriding: When a subclass contains a method with the same name and signature as in the super class then it is called as method overriding.
- 18. Summery • An object is an instance of a class. • Using abstraction one can simulate real world objects. • Abstraction provides advantage of code reuse • Abstraction enables program open for extension • Encapsulation provides the security that keeps data and methods safe from inadvertent changes. • Inheritance is parent-child relationship of class which is mainly used for code reusability. • Polymorphism definition is that Poly means many and morphos means forms.