Java Tutorial
Last Updated :8 Dec, 2025
Java is a high-level, object-oriented programming language used to build web apps, mobile applications, and enterprise software systems.
- Known for its Write Once, Run Anywhere capability, which means code written in Java can run on any device that supports the Java Virtual Machine (JVM).
- Syntax and structure is similar to C-based languages like C++ and C#.
Basic Code Example
The following is a simple program that displays the message “Hello, World!” on the screen.
To understand working of this code, refer Java Introduction.
Why Learn Java?
- Used to build Android apps, desktop and web apps, enterprise backend systems, and cloud-based software.
- In high demand with many job opportunities in software development.
- Has popular frameworks like Spring and Hibernate which makes it powerful for enterprise applications.
- Supports object-oriented programming for clean, maintainable and reusable code.
- Top companies like Amazon, Netflix, and LinkedIn use Java.
Basics
Java basics form the foundation of your programming journey, covering essential concepts like syntax, data types, variables, loops, and conditionals.
- Introduction
- Download and Install Java
- JDK vs JRE vs JVM
- Identifiers
- Keywords
- Quiz: Java Basics
- Data Types
- Variables
- Operators
- Quiz: Variables, Operator
- Decision Making
- Loops & Jump Statements
- Quiz: Control Statements and Loops
- Project: Number Guessing Game
Methods
Java methods are reusable blocks of code that perform specific tasks and help organize your program. They improve code readability, reduce repetition, and make debugging easier.
- Introduction to Methods
- Static Methods vs Instance Methods
- Access Modifiers
- Command Line Arguments
- Variable Arguments (Varargs)
- Quiz: Methods
Arrays
Java arrays are containers that store multiple values of the same data type in a single variable. They provide an efficient way to manage and access collections of data using index-based positions.
- Introduction
- Declare and Initialize Arrays
- Multi-Dimensional Arrays
- Quiz: Java Arrays
- Jagged Arrays
- Arrays Class
- Final Arrays
- Quiz: Array
- Projects: Tic-Tac-Toe Game
Strings
Java Strings represent sequences of characters and are widely used in text processing. They are immutable, meaning once created, their values cannot be changed.