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Robert
Robert

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Java and OOP in general

  1. Java Fundamentals: JVM, JDK, JDE Java operates on three essential components: Java Virtual Machine (JVM): It acts as a bridge between the Java code and the underlying hardware. JVM interprets bytecode, allowing Java applications to run on diverse devices without recompilation. Java Development Kit (JDK): A comprehensive toolkit for Java developers, JDK includes the Java Compiler (javac) to convert code into bytecode, libraries, and various tools crucial for app development. Java Development Environment (JDE): Often represented by Integrated Development Environments (IDEs) like Eclipse or IntelliJ IDEA, it provides a user-friendly interface for writing, debugging, and running Java code.
  2. Types in Java Java, like many programming languages, has various types used to define data: Primitive Types: These include basic data types like int, boolean, double, etc., and hold simple values directly. Non-Primitive Types: Also known as reference types, these include objects, arrays, and strings. They refer to complex data structures and are stored as references.
  3. Differences between Primitive and Non-Primitive Types Primitive types directly hold values, whereas non-primitive types hold references to objects. Primitive types are stored in the stack memory, while non-primitive types are stored in the heap memory. Primitive types are immutable, whereas non-primitive types are mutable and can be modified.
  4. Object-Oriented Programming (OOP) Java is deeply rooted in the principles of Object-Oriented Programming. OOP emphasizes building software using objects and classes, promoting modularity, reusability, and flexibility in code.
  5. The 4 Pillars of OOP in Java Inheritance: It allows a new class (subclass/child class) to inherit properties and behavior from an existing class (superclass/parent class). Encapsulation: This principle hides the internal workings of an object and exposes only the necessary functionalities through methods. Abstraction: It focuses on displaying essential features without including the background details, simplifying complex systems for the user. Polymorphism: It enables objects of different classes to be treated as objects of a common superclass, allowing methods to be called on them interchangeably.

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