☕ Java Tutorial

A hands-on, example-driven Java learning repository — from zero to OOP hero.

"Learning Java one concept at a time — clean code, clear examples, no fluff."

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🧭 Table of Contents

• About
• What's Inside
• Topics Covered
• Getting Started
• Learning Path
• Code Samples
• Contributing
• Author

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📖 About

java-tutorial is a structured, example-first repository built to teach core Java concepts through practical, runnable code. With 327+ commits and growing, it's a living reference for developers at every stage — whether you're writing your first class or revisiting fundamentals before an interview.

Each folder isolates one concept, with focused .java files you can read, run, and experiment with immediately. No frameworks, no setup headaches — just pure Java.

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📦 What's Inside

☕ java-tutorial/
│
├── 📂 Access-Modifiers/           # public, private, protected, default — demystified
├── 📂 Consept-Of-Object-Oriented/ # The 4 pillars of OOP with real examples
├── 📂 Constructor/                # Default, parameterized & overloaded constructors
│
└── 📄 README.md

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🗂 Topics Covered

🔐 Access Modifiers

Control who can see and touch your code.

Modifier	Visibility
public	Accessible from anywhere
protected	Same package + subclasses
default	Same package only
private	Class-only access

Learn when and why to use each modifier — a critical skill for writing safe, maintainable Java.

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🧱 Concept of Object-Oriented Programming (OOP)

The four pillars that make Java Java.

Pillar	What It Means
🔒 Encapsulation	Bundle data and methods; hide internals
🧬 Inheritance	Reuse and extend existing classes
🎭 Polymorphism	One interface, many implementations
🎨 Abstraction	Expose what matters, hide the rest

Practical code examples show each concept in action — not just definitions.

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🏗️ Constructors

How Java objects are born.

• Default Constructor — no arguments, sensible defaults
• Parameterized Constructor — initialize with specific values
• Constructor Overloading — multiple signatures, flexible creation
• this() chaining — constructor calling constructor

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🚀 Getting Started

Prerequisites

• ✅ JDK 8+ installed
• ✅ Any IDE: IntelliJ IDEA, Eclipse, or VS Code with Java extension
• ✅ Basic familiarity with running terminal commands

Clone & Run

# Clone the repository
git clone https://github.com/MisaghMomeniB/java-tutorial.git

# Move into the project
cd java-tutorial

# Navigate to a topic folder
cd Access-Modifiers

# Compile a file
javac FileName.java

# Run it
java FileName

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🗺️ Learning Path

Follow this order for the smoothest journey from beginner to confident Java developer:

1️⃣  Access-Modifiers
        │
        ▼
2️⃣  Constructor
        │
        ▼
3️⃣  Consept-Of-Object-Oriented
        │
        ▼
4️⃣  Build your own Java project! 🚀

Each step builds on the last. Don't skip — understanding access modifiers makes OOP click much faster.

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💡 Code Samples

Access Modifier Example

public class BankAccount {
    private double balance;       // only this class can access it
    protected String ownerName;   // accessible by subclasses
    public String accountId;      // everyone can see this

    public double getBalance() {  // controlled access via public method
        return balance;
    }
}

Constructor Example

public class Person {
    String name;
    int age;

    // Default constructor
    Person() {
        this.name = "Unknown";
        this.age = 0;
    }

    // Parameterized constructor
    Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
}

// Usage
Person p1 = new Person();                   // → Unknown, 0
Person p2 = new Person("Misagh", 25);       // → Misagh, 25

OOP — Inheritance Example

class Animal {
    void speak() {
        System.out.println("...");
    }
}

class Dog extends Animal {
    @Override
    void speak() {
        System.out.println("Woof! 🐕");
    }
}

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🛣️ Roadmap — Upcoming Topics

• Access Modifiers
• Constructors
• OOP Concepts (Encapsulation, Inheritance, Polymorphism, Abstraction)
• Exception Handling ⚠️
• Collections Framework (List, Map, Set) 📚
• Interfaces & Abstract Classes 🎭
• Generics 🔮
• File I/O 📁
• Multithreading 🧵
• Java Streams & Lambda Expressions ⚡

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🤝 Contributing

All contributions are welcome — whether it's a new topic, a cleaner example, or a typo fix!

1. Fork the repo
2. Create a branch: git checkout -b topic/your-topic
3. Add your Java files with clear comments
4. Commit: git commit -m "Add: topic name"
5. Push and open a Pull Request

Please keep examples focused, well-commented, and beginner-friendly.

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📄 License

Distributed under the MIT License — free to use, learn from, and share.

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👨‍💻 Author

Misagh Momeni Bashusqeh Software Developer

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Made with ☕ and a passion for clean, teachable code. Star ⭐ the repo if it helped you — it means a lot!