Topic 1: Introduction to Java & Program Structure

Q: What is Java?

A high-level, object-oriented, and platform-independent programming language developed by Sun Microsystems (now Oracle).

Q: What does "platform-independent" mean in Java?

It means Java code can run on any operating system that has a Java Virtual Machine (JVM).

Q: What is the JVM?

The Java Virtual Machine runs Java bytecode and enables Java’s platform independence.

Q: What is the JDK?

The Java Development Kit is a software development environment that includes tools like the compiler (javac), debugger, and Java libraries.

Q: What is the JRE?

The Java Runtime Environment includes the JVM and standard Java libraries. It allows users to run Java applications.

Q: What is bytecode in Java?

Bytecode is the intermediate code (.class files) generated by the Java compiler and executed by the JVM.

Q: What is a Java class?

A class is a blueprint for creating objects. It defines fields (state) and methods (behavior).

Q: What is the entry point of a Java application?

The main method: public static void main(String[] args)

Q: What are comments in Java?

Comments are ignored by the compiler and are used to describe code. Types: single-line (//), multi-line (/* /), and Javadoc (/* */).

Q: What is the naming convention for Java source files?

The filename should match the public class name and have a .java extension. Example: MyClass.java