Daily diary of my progress learning Java, with code examples and summaries.
This repository contains a chronological, day-by-day record of my Java learning process, focusing on core Java concepts and Data Structures & Algorithms (DSA) as taught in the Apna College Alpha Batch 5.0 course. Each Day-XX/ folder holds one or more .java source files for code examples and a summary.md that explains what I learned on that particular day.
- Day 01 – Java Basics: Boilerplate, I/O, Variables & DataTypes
- Day 02 – Java: Data Types, Type Conversion, Operators, and Execution Flow
- Day 03 – Java: Conditional Statements
- Day 04 – Java: Loop & Control Flow
- Day 05 – Java: Pattern Printing with Nested Loops
- Day 06 – Java: Functions & Function Overloading
- Day 07 – Java: Prime Number Functions, Number Conversions & Java Scope
- Day 08 – Java: Advanced Pattern Printing
- Day 09 – Java: Arrays
- Day 10 – Java: Arrays Advanced Problems & Optimization
- Day 11 – Java: Array Sorting Algorithms
- Day 12 – Java: 2D Array
- Day 13 – Java: Strings
- Day 14 – Java: Strings (Advanced)
- Day 15 – Java: Bit Manipulation
- Day 16 – Java: Object-Oriented Programming
- Day 17 – Java: Introduction to Recursion
- Day 18 – Java: Divide & Conquer Algorithms
- Day 19 – Java: Time & Space Complexity
- Day 20 – Java: Time and Space Complexity Analysis
- Day 21 – Java: Introduction to Backtracking
- Day 22 – Java: Introduction to ArrayList
- Day 23 – Java: Singly Linked List
- Day 24 – Java: Linked List Loops & Java Collections Framework
- Day 25 – Java: Advanced Linked List Techniques
- Day 26 – Java: Stacks
- Day 27 – Java: Advanced Stack Problems
- Day 28 – Java: Queues
- Day 29 – Java: Queues, Deques & Related Problems
- Day 30 – Java: Greedy Algorithms
- Day 31 – Java: Binary Trees
- Day 32 – Java: Advanced Binary Tree Operations
- Day 33 – Java: Binary Search Tree (BST)
- Day 34 – Java: Balancing BSTs & Introduction to AVL Trees
- Day 35 – Java: Heaps & Priority Queues
- Day 36 – Java: Hashing
- Day 37 – Java: Tries
- Day 38 – Java: Introduction to Graphs
- Day 39 – Java: Graph Traversals & Components
- Day 40 – Java: Advanced Graph Algorithms
- Day 41 – Java: Advanced Graph Techniques
Java-Learning-Journey/
│
├─ README.md ← This file (project overview, TOC, prerequisites, etc.)
├─ LICENSE ← Apache 2.0 license text
├─ .gitignore ← Standard Java ignores (compiled classes, IDE metadata, etc.)
│
├─ Day-XX/ ← Folder for Day XX
│ ├─ *.java ← Example: System.out.println and console output basics
│ └─ summary.md ← Summary of Day XX topics
│
└─ …
Before you clone and run the examples, ensure you have:
-
Java Development Kit (JDK 24.0.1)
- I’m using
jdk-openjdk-24.0.1.u9-1. - You can download from OpenJDK 24 or install via your distribution’s package manager.
- I’m using
-
Visual Studio Code (VSCode) (or any Java-compatible IDE)
- I run and debug these examples in VSCode with the “Java Extension Pack.”
- You can also use IntelliJ IDEA, Eclipse, or any editor that supports Java 24.
-
Git
-
To clone this repository:
git clone https://github.com/sumoondev/Java-Learning-Journey.git
-
You can compile and run each day’s Java examples from the project root. Replace Day-XX with the desired folder number.
-
Navigate into the repository
cd Java-Learning-Journey -
Compile a single file
# Example: Compile Day-XX’s FileName.java javac Day-XX/FileName.java -
Run the compiled class
# Example: Run the Day-XX FileName class java -cp Day-XX FileName -
Compile all
.javafiles in a folder# Example: Compile all examples in Day-XX javac Day-XX/*.java
-
Run a specific main class
# Example: Run the File2 example in Day-XX java -cp Day-XX File2
Tip: If you prefer an IDE workflow, open the root folder in VSCode (or your favorite IDE) and use its built-in Run/Debug features to compile and execute each file.
Contributions are welcome! If you spot:
- A typo or formatting issue in any
summary.md - A bug or optimization opportunity in one of the
.javaexamples - A suggestion for reorganizing folder structure, naming conventions, or documentation
…please feel free to open a Pull Request or an Issue. I’m eager to learn from feedback and continuously improve both the content and my Java/DSA skills.
When contributing:
- Fork the repository.
- Create a new branch, named descriptively (e.g.,
feature/day-07-summary). - Make your changes (add code, update summaries, fix typos).
- Commit and push your branch.
- Open a Pull Request with a clear description of what you changed and why.
This project is licensed under the Apache License 2.0. See the LICENSE file for the full terms and conditions.
Copyright 2025 Sumoon Byanjankar
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Thank you for following my Java Learning Journey! If you have questions, ideas, or feedback, don’t hesitate to open an Issue or Pull Request. Happy coding! 😊