☕ Core Java – Complete Fundamentals Guide

🚀 This repository covers Core Java concepts from basics to advanced fundamentals, designed for students, freshers, and interview preparation.
It builds a strong foundation required for Advanced Java, Spring, and Backend Development.

---

📌 What You’ll Learn

✅ Java basics to advanced concepts
✅ Object-Oriented Programming (OOP)
✅ Exception handling & memory concepts
✅ Collections & multithreading
✅ Java 8 features
✅ Interview-ready explanations

---

🧩 Topics Covered

🔹 Java Basics

📘 Introduction to Java

• Java definition & features
• JDK vs JRE vs JVM
• Java vs C++ vs Python
• Data Types
• Variables & Keywords
• Operators
• Control Statements (if, switch, loops)

---

🔹 Object-Oriented Programming (OOP)

🧠 Core OOP pillars

• Class & Object
• Encapsulation
• Inheritance
• Polymorphism
• Abstraction
• Constructors
• this & super keyword

---

🔹 Strings

🔤 String handling in Java

• String class
• StringBuffer & StringBuilder
• Immutable vs Mutable
• Common String methods

---

🔹 Arrays

📦 Data storage concepts

• One-dimensional arrays
• Multi-dimensional arrays
• Array operations
• Arrays vs Collections

---

🔹 Exception Handling

⚠️ Handling runtime errors

• Checked & Unchecked exceptions
• try-catch-finally
• throw & throws
• Custom exceptions

---

🔹 Multithreading

⚙️ Concurrent programming

• Thread class
• Runnable interface
• Thread lifecycle
• Synchronization
• Inter-thread communication

---

🔹 Collections Framework

🗂️ Data structures in Java

• List (ArrayList, LinkedList)
• Set (HashSet, TreeSet)
• Map (HashMap, TreeMap)
• Comparable & Comparator
• Iterator & ListIterator

---

🔹 Java 8 Features

✨ Modern Java concepts

• Lambda expressions
• Functional interfaces
• Stream API
• Method references
• Optional class

---

🔹 Wrapper Classes & Generics

📦 Type safety & utilities

• Wrapper classes
• Autoboxing & Unboxing
• Generics (class, method, wildcard)

---

🔹 File Handling & IO

📁 Input/Output operations

• File class
• FileReader & FileWriter
• BufferedReader & BufferedWriter
• Serialization & Deserialization

---

🔹 JVM & Memory Management

🧩 Internal working of Java

• JVM architecture
• ClassLoader
• Heap & Stack memory
• Garbage Collection

---

📂 Project Structure (Example)

Core-Java/ │ ├── Basics/ ├── OOP/ ├── Strings/ ├── Arrays/ ├── Exception-Handling/ ├── Multithreading/ ├── Collections/ ├── Java8/ ├── File-Handling/ ├── JVM-Memory/ └── README.md

---

🎯 Interview Preparation Focus

💡 Frequently asked Core Java interview questions
💡 Concept clarity with examples
💡 Beginner → Advanced learning path

Ideal for:

• Java Developer interviews
• Freshers & Students
• Placement preparation
• Backend development foundation

---

🎓 Who Should Use This Repository?

👨‍🎓 Computer Science students
👨‍💻 Java beginners
📘 Interview aspirants
🧠 Anyone strengthening Java fundamentals

---

🛠️ Prerequisites

✔️ Basic programming knowledge (any language)
✔️ Logical thinking
✔️ Willingness to learn ☺️

---

⭐ How to Use This Repository

1️⃣ Start with Java Basics
2️⃣ Move to OOP concepts
3️⃣ Practice Collections & Multithreading
4️⃣ Revise Java 8 features
5️⃣ Prepare for interviews

---

🤝 Contributing

Contributions are welcome!
You can fork, add examples, or improve explanations.

---

📬 Contact

📧 Email: mahesh.kale.cse@gmail.com
🔗 LinkedIn: [https://www.linkedin.com/in/mahesh-kale-cse/]

---

⭐ If this repository helps you, please give it a star! ⭐