Programming Basics
From your first HelloWorld to production-grade code — variables, control flow, OOP, collections, concurrency, I/O.
Prerequisites
Can open a terminal, type javac / python3. If you've never written a line of code, start from Vol 0.
Prior knowledge: Any programming language basics, or completed Vol 0
Volume positioning: The core foundation of this atlas. Whether your goal is backend, AI, or systems, the concepts here are your building blocks.
Completion milestone: Can independently write a multi-file project with proper OOP design, use collections and exception handling, understand basic concurrency concepts.
Primary language: Java (with Python/C++ comparison windows)
Pre-requisite Self-Test
If you're not sure whether to start from here, try these questions:
- [ ] Can you define a variable and assign a value?
- [ ] Can you write a loop (for/while)?
- [ ] Can you write a function/method with parameters?
- [ ] Do you know what a class and an object are?
- [ ] Can you use an array or a list?
If you answered "yes" to all five, you can skim through the first few chapters. If you're unsure about three or more, start from ch01.
Chapter Overview
| Chapter | Topic | Time | Difficulty |
|---|---|---|---|
| Ch01 | First Program | 30 min | |
| Ch02 | Variables & Types | 40 min | |
| Ch03 | Expressions & Operators | 40 min | |
| Ch04 | Control Flow | 50 min | |
| Ch05 | Methods & Stack | 60 min | |
| Ch05+ | Recursion | 45 min | |
| Ch06 | Arrays | 55 min | |
| Ch07 | OOP: Classes & Objects | 65 min | |
| Ch08 | OOP: Inheritance & Polymorphism | 45 min | |
| Ch08+ | Lambda & Higher-Order Functions | 40 min | |
| Ch09 | Strings & Utilities | 3-4 hrs | |
| Ch10 | Core Collections | 5-7 hrs | |
| Ch11 | Exception Handling | 4-6 hrs | |
| Ch12 | Generics | 5-8 hrs | |
| Ch13 | Annotations, Reflection & Metaprogramming | 70 min | |
| Ch14 | Concurrency Basics | 90 min | |
| Ch15 | I/O & Files | 5-7 hrs |
What You'll Build
By the end of this volume, you will have built:
- A library management system (ch07-08)
- A logging analyzer (ch09-10)
- A multi-threaded bank transfer simulator (ch11, ch14)
- A file-processing pipeline (ch15)
This volume has 15+3 chapters, all complete