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Java Tutorial

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Java Introduction What is Java?History & Features JDK vs JRE vs JVM How Java Works Install Java & Setup First Java Program Java vs Other Languages

Syntax & Structure Java Keywords & Reserved Words Naming Conventions Data Types Variables Type Casting Operators Increment & Decrement Operators Escape Sequences Math Class User Input (Scanner)Command Line Arguments Wrapper Classes Autoboxing & Unboxing final Keyword Comments

if Statement if-else Statement else-if Ladder Nested if switch Statement for Loop while Loop do-while Loop for-each Loop Nested Loops break Statement continue Statement return Statement

Methods Overview Parameters & Return Types Method Overloading Recursion Variable Arguments (varargs)Pass by Value vs Pass by Reference

Arrays Overview Multi-dimensional Arrays Arrays class Passing Arrays to Methods

String Overview String Methods String Comparison equals() vs ==String Pool StringBuilder StringBuffer String vs StringBuilder vs StringBuffer Immutable Strings String Formatting String Class Deep Dive

Packages in Java Creating Custom Packages import Statement Access Modifiers Deep Dive public Access Modifier private Access Modifier protected Access Modifier default Access Modifier

Inner Classes Static Nested Class Anonymous Classes Enums Records (Java 16+)Sealed Classes (Java 17+)Immutable Classes Object Cloning Shallow vs Deep Copy Annotations Built-in Annotations Custom Annotations Reflection API

What is Exception Handling?Exception vs Error Exception Hierarchy Checked vs Unchecked Exceptions Common Java Exceptions try-catch Multi-catch finally Block try-with-resources throw Keyword throws Keyword throw vs throws Custom Exceptions Exception Propagation

Generics Overview Why Generics?Generic Classes Generic Interfaces Generic Methods Bounded Type Parameters Wildcards (?)Upper-Bounded Wildcards (? extends)Lower-Bounded Wildcards (? super)Generics in the Collections Framework Type Inference (Diamond Operator)Type Erasure What Generics Cannot Do

Lambda Expressions Functional Interfaces Method References Predicate Function Consumer Supplier Optional

Streams Overview filter()map()forEach()reduce()collect()sorted()distinct()limit()skip()Collectors & groupingBy()Parallel Streams Stream vs Parallel Stream

Introduction to Date & Time API LocalDate LocalTime LocalDateTime ZonedDateTime Period Duration DateTimeFormatter Legacy Date vs New API

Java 8 Key Features Java 11 Features Java 17 Features Java 21 Features var (Local Type Inference)Text Blocks Pattern Matching Switch Expressions Virtual Threads (Java 21)

File & Path Overview Reading Files Writing Files BufferedReader & Writer NIO.2 (java.nio)Serialization Externalization Serialization vs Externalization

Threads Overview Runnable & Callable Thread Lifecycle Synchronization volatile Keyword Race Conditions Deadlock Livelock Starvation wait, notify & notifyAll Lock & ReentrantLock Semaphore Atomic Variables ConcurrentHashMap Executor Framework CompletableFuture ForkJoinPool

JVM Architecture Stack Memory Heap Memory Stack vs Heap Memory Garbage Collection Metaspace vs PermGen ClassLoader JIT Compiler

Java Tutorial

What is Java?

Java is a high-level, class-based, object-oriented programming language designed to have as few implementation dependencies as possible. It follows the "Write Once, Run Anywhere" principle — compiled Java code runs on any platform that supports the JVM without recompilation.

Our tutorial covers everything from basics to modern Java — including OOP, Collections, Streams, Multithreading, Generics, Design Patterns, Modern Java 8–21, and more.

Beginners Guide

Practice Problems

Learning Roadmap

Introduction

Basics

Control Flow

Methods

Arrays

Strings

›String Overview
›String Methods
›String Comparison
›equals() vs ==
›String Pool
›StringBuilder
›StringBuffer
›String vs StringBuilder vs StringBuffer
›Immutable Strings
›String Formatting
›String Class Deep Dive

OOP

Packages & Access Control

Advanced OOP

Exception Handling

Collections Framework

The Java Collections Framework provides ready-made data structures — List, Set, Map, Queue, and more. Understanding when and how to use each collection is a core Java skill.

Generics

Generics allow you to write type-safe, reusable code. Learn how to parameterize classes and methods, understand wildcards, and avoid ClassCastExceptions at runtime.

Functional Programming

Streams

Date & Time API

Modern Java

File I/O

Multithreading

JVM & Memory