☕ Java Learning Notes

Personal Java learning repository — handwritten notes converted to markdown summaries with hands-on practice code, organised topic by topic.

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🔗 Quick Navigation

📓 Scanned Notebook Pages	Thumbnail preview of every topic's handwritten notes
📚 Topics Overview	Quick-link table — notes + code for each topic
📁 Repo Structure	Full folder layout explained
🚀 How to Run	Compile and run any Java practice file
🎯 Next Topics	Upcoming topics checklist

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📓 Scanned Notebook Pages

Click any thumbnail below to open the scanned PDF for that topic.

01. Introduction to Java Notebook p. 1  ·  1 page What is Java, history, features, WORA, famous apps	02. JVM / JDK / JRE Notebook p. 3–13  ·  11 pages Architecture, class loader, memory areas, execution engine, JNI	03. Hello World Program Notebook p. 2, 15–20, 63–65  ·  10 pages Class definition, main method, System.out.println, command-line args
04-05. Data Types & Variables Notebook p. 21–24  ·  4 pages Primitive types, float/double rules, local/instance/static variables	06. Operators Notebook p. 25–33  ·  9 pages Arithmetic, logical, bitwise AND/OR/XOR/shift, instanceof, inc/dec	07. Keywords & Identifiers Notebook p. 34–37  ·  4 pages 53 reserved words, keyword categories, identifier rules
08. Wrapper Classes Notebook p. 38–45  ·  8 pages Autoboxing, unboxing, 14 methods, integer cache, == vs .equals()	09. Decision Making Notebook p. 46  ·  1 page if/else, if-else-if, nested-if, ternary, switch, enhanced switch	10. Loops Notebook p. 47  ·  1 page for, for-each, while, do-while with examples and valid variants
11. Jump Statements Notebook p. 48  ·  1 page continue, break, return, break with labels (goto alternative)	12. Methods Notebook p. 49–57  ·  9 pages Instance vs static, getters/setters, call stack, predefined methods	13. Access Modifiers Notebook p. 58–62  ·  5 pages private, default, protected, public — scope rules with examples

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📚 Topics Overview

#	Topic	Notes	Practice Code	Notebook Pages
01	Introduction to Java	📄 notes	💻 code	p. 1
02	JVM / JDK / JRE	📄 notes	—	p. 3–13
03	Hello World Program	📄 notes	💻 code	p. 2, 15–20, 63–65
04	Data Types	📄 notes	💻 code	p. 21–22
05	Variables	📄 notes	💻 code	p. 22–24
06	Operators	📄 notes	💻 code	p. 25–33
07	Keywords & Identifiers	📄 notes	—	p. 34–37
08	Wrapper Classes	📄 notes	💻 code	p. 38–45
09	Decision Making	📄 notes	💻 code	p. 46
10	Loops	📄 notes	💻 code	p. 47
11	Jump Statements	📄 notes	💻 code	p. 48
12	Methods	📄 notes	💻 code	p. 49–57
13	Access Modifiers	📄 notes	💻 code	p. 58–62

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📁 Repository Structure

java-learning-notes/
├── README.md                          ← you are here
├── PROGRESS.md                        ← topic-by-topic checkbox tracker
│
├── notes/                             ← markdown summaries (13 files)
│   ├── 01-introduction.md
│   ├── 02-jvm-jdk-jre.md
│   ├── 03-hello-world.md
│   └── ... (10 more)
│
├── src/                               ← Java practice code
│   ├── 01-basics/                     HelloWorld.java · DataTypes.java
│   ├── 02-variables/                  Variables.java
│   ├── 03-operators/                  Operators.java
│   ├── 04-wrapper-classes/            WrapperClasses.java
│   ├── 05-decision-making/            DecisionMaking.java
│   ├── 06-loops/                      Loops.java
│   ├── 07-jump-statements/            JumpStatements.java
│   ├── 08-methods/                    Methods.java
│   └── 09-access-modifiers/           AccessModifiers.java
│
└── resources/                         ← scanned notebook PDFs
    ├── thumbnails/                    ← first-page preview PNGs (used by README)
    │   ├── page-01-introduction.png
    │   └── ... (12 PNGs total)
    ├── page-01-introduction.pdf
    └── ... (12 PDFs total)

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🚀 How to Run Practice Files

# navigate to the topic folder
cd src/01-basics

# compile
javac HelloWorld.java

# run
java HelloWorld

# run with command-line arguments
java HelloWorld 10 20 Kishor

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🎯 Next Topics to Cover

• OOP — Classes, Objects, Constructors
• Inheritance
• Polymorphism
• Abstraction & Interfaces
• Exception Handling
• Collections Framework
• Generics
• File I/O
• Multithreading

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Notes by HQ  ·  Java learning journey