A complete Java learning platform with structured lessons, practical examples, coding practice, DSA, interview preparation, projects, and an online Java compiler.
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}Track your learning journey
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Everything you need to master Java programming in one place
Start from absolute basics. No prior programming experience required.
From introduction to Java Streams. Organized in a logical learning path.
Every concept comes with practical, runnable code examples.
Complete DSA course with Java implementations and practice problems.
Hands-on coding practice across all Java topics.
All notes are completely free. Learn at your own pace.
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Your path from beginner to job-ready Java developer
Variables, Data Types, Operators
Conditions, Loops, Switch
Classes, Inheritance, Polymorphism
Collections, String Handling
Exceptions, Multithreading, Streams
Data Structures & Algorithms
375+ Coding Problems
Build Real Applications
100+ Questions & Answers
Start your Java career
Complete DSA course covering all essential topics for coding interviews and placements. Based on structured handwritten notes and curated practice problems.
Select a topic from the sidebar to begin learning.
Variables, I/O, conditions, loops, methods
Big-O, Big-Ω, Big-Θ, time & space
Traversal, searching, two pointer, Kadane's
String methods, palindrome, anagram
Bubble, Selection, Merge, Quick, Heap Sort
Base case, recursive call, stack memory
Singly, doubly, circular linked lists
LIFO, FIFO, deque, applications
HashMap, HashSet, frequency counting
Traversals, BST operations, heaps
BFS, DFS, Dijkstra, MST, topological sort
Memoization, tabulation, 1D/2D DP, knapsack
Activity selection, knapsack, Huffman
AND, OR, XOR, shift operators
Two pointers, sliding window, monotonic stack
ArrayList, HashMap, TreeSet, PriorityQueue
Follow this path from beginner to advanced Java developer
Sharpen your skills with hands-on exercises
Star patterns, number patterns, Floyd's triangle, butterfly pattern, and more.
Find min/max, sort arrays, rotate array, merge arrays, find duplicates.
Reverse strings, palindrome check, anagram, substring search.
Test your knowledge with multiple choice questions from all chapters.
Write and run Java code directly in your browser.
Find and fix bugs in pre-written Java code.
Build real-world applications with Java
A simple calculator application with basic arithmetic operations
Simulate ATM operations like withdraw, deposit, and balance check
Interactive game where users guess a random number
Manage books, members, and borrowing operations
Full banking system with accounts, transactions, and transfers
Manage employee records with CRUD operations
Common Java interview questions organized by topic
Complete Java reference book with 180 chapters covering everything from basics to advanced topics. Extracted from JavaNotesForProfessionals.pdf (976 pages).
Select a chapter from the sidebar to begin reading.