Java: An Introduction

 Java: An Introduction

Java is a widely-used, object-oriented programming language known for its security, speed, and cross-platform compatibility. Originally developed by Sun Microsystems in 1995 and now owned by Oracle, Java boasts vast community support and is a staple in enterprise applications.

Java as a Statically Typed Language

          Java, like C and C++, enforces strict type declarations, ensuring:

• Early Error Detection: Possible issues are reported at compile time.

• Optimized Performance: Type-specific optimizations enhance execution speed (often 5x-10x faster than interpreted languages like Python).

• Structured Code Management: Developers must explicitly define data types for better program stability.

Why Choose Java Over C/C++?

• Simpler Syntax: Java is easier to learn than C++.

• Larger Standard Library: Java offers extensive built-in functionalities.

• Cross-Platform Compatibility: Java applications run on various operating systems via the Java Virtual Machine (JVM).

Java Applications & Career Paths

Java is used in:

• Mobile Development (Android apps)

• Web & Desktop Applications

• Server-Based Systems

Career roles include:

• Java Developer

• Java Architect

• Java Web Developer

• Java Android Developer

Java Syntax & Basics :

Hello World Program :

Introduction to Java - Basics, Syntax, and Development

• Class Definition: Every Java program starts with a class.

• Main Method: The execution entry point (main).

System.out.println(): Prints output to the console.



Arithmetic Operations :

        Variables in Java :

                A variable acts as a container for storing data. Java enforces static typing, meaning                        variable types must be declared explicitly.

           Declaring & Initializing Variables:

                

Introduction to Java - Basics, variables

• Declaration: Specifies a variable’s type.

• Initialization: Assigns an initial value.

Definition: Combines declaration and initialization.

Key Variable Rules in Java:

          Declaration Before Use: Variables must be declared before being accessed.

            Fixed Data Type: Once declared, a variable’s type cannot be changed.

            

        Summary

• Java is a secure, fast, and cross-platform programming language.

• It is statically typed, requiring explicit data type declarations.

• Java supports fundamental arithmetic operations (+, -, *, /, %).

• Variables must be declared before use, and their types cannot change once assigned.