📖 Lecture 1: Introduction to Java and Data Types

• What is Java: Created in 1995 and currently owned by Oracle, Java is a versatile programming language used for mobile apps (like Android), desktop applications, web servers, and games [1].
• How Java Works: The programmer writes code in a .java file [2]. The Java Compiler (javac) translates this high-level code into Bytecode (.class file) [3]. Finally, the Java Virtual Machine (JVM) executes the Bytecode on the operating system, making Java platform-independent [3].
• Java Architecture: The Java Development Kit (JDK) contains the Java Runtime Environment (JRE) and development tools. The JRE contains the JVM and libraries necessary to run Java programs [3].
• Basic Syntax: Every Java program must have a public class with a name matching the filename [2]. Code execution begins inside the public static void main(String[] args) method [2].
• Comments: You can use // for single-line comments and /* ... */ for multi-line comments [2].
• Data Types:
  • Primitive: Numeric integer types (byte, short, int, long), numeric floating-point types (float, double), and non-numeric types (char, boolean) [2].
  • Non-Primitive: Strings, Arrays, and User-defined classes [2].