oop

• Object-Oriented Programming (OOP) is a methodology to design a program using classes and objects
• OOP aims to implement real-world entities like inheritance, hiding, and polymorphism in programming
• The primary purpose of a class is to store data and information
• An object is any entity that has state and behavior
• An object can be defined as an instance of a class
• Inheritance is when one object acquires all the properties and behaviors of a parent object
• Polymorphism is when one task is performed in different ways
• In Java, method overloading and method overriding are used to achieve polymorphism
• Abstraction is hiding internal details and showing functionality
• In Java, abstract class and interface are used to achieve abstraction
• Encapsulation is binding code and data together into a single unit
• A Java class is an example of encapsulation
• Advantages of OOP over Procedure-oriented programming language
• OOP makes development and maintenance easier
• OOP provides data hiding
• OOP provides the ability to simulate real-world events more effectively
• Java is a popular programming language and platform used in various applications
• Java is used in desktop, web applications, scientific supercomputers, gaming consoles, cell phones, and the Internet
• Java was initially named "Oak" in 1991 for consumer electronic appliances
• Java was developed by James Gosling at Suns Micro System
• Oak was redesigned in 1995 and renamed Java for internet applications
• Characteristics of Java
• Java is a simple, easy to write, and readable language
• Java has a concise set of features making it easy to learn
• Java is an object-oriented programming language with features drawn from C++
• Java is platform-independent, robust, supports multi-threading, and offers high performance
• Java provides strong security, portability, and a secure way to access web applications
• Java Technology includes programming, development, application, and deployment environments
• Java can create various applications using conventional programming languages
• Java technology applications run on any machine with Java Runtime Environment (JRE)
• Phases of Java Program
• Java source file must have the same name as a public class it declares
• Java source file can contain only one public class declaration
• Java source file extension must be .java and filename is case-sensitive
• Java programs need to be written, compiled into bytecode, and interpreted by the Java Virtual Machine (JVM)
• Summary of the Phases of Java Program
• Java programs need to be compiled to bytecode and then converted to machine code when run
• In OOP, objects model real-world objects and consist of important concepts like Encapsulation, Polymorphism, Inheritance, and Abstraction
• In Java, the state is the set of values of an object's variables and behavior is implemented as methods