🚀 Why I Created a Repository of Top Java Interview Questions

As a Java developer actively preparing for interviews, I often struggled to find one single place that had clean code, terminal-friendly Java files, and clear explanations. Most online platforms give theoretical content, or code that doesn't run well in terminal or VS Code. So, I decided to build my own repository: Top 100+ Java Coding Interview Questions with Solutions and Explanations. This blog walks through the structure, content, and practical benefits of the project — and how it can help you crack real-world interviews. ---

📁 What This GitHub Repo Contains

The repository contains 100+ Java coding questions covering:

• Basic to Advanced Java logic building
• Mathematical problems (factorial, reverse, palindrome, etc.)
• Array operations (sorting, searching)
• String manipulation (anagrams, reverse, count)
• Recursion, loops, conditions
• And many real-world coding round questions

Each file is named clearly like: 1_add_two_numbers.java, 2_swap_two_numbers.java, 3_reverse_integer.java All files are written in a format where they can be directly executed from terminal without worrying about `public class` issues — a huge time-saver for VS Code or CLI users. ---

🧠 Sample Question Breakdown: Reverse an Integer

Let’s walk through one example from the repo:

import java.util.Scanner;

public class reverse_integer {
    public static void main(String[] args) {
        long num = new Scanner(System.in).nextLong();
        long rev = 0;

        while(num != 0){
            long digit = num % 10;
            rev = rev * 10 + digit;
            num /=10;
        }

        System.out.println("Reversed Number: " + rev);
    }
}

💡 Explanation: This program reads a long integer and reverses its digits. It avoids integer overflow by using `long` type, which is better than `int` for large numbers. ---

📦 Folder Structure

java-interview-questions/
├── 1_add_two_numbers.java
├── 2_swap_two_numbers.java
├── 3_reverse_integer.java
├── 4_factorial_loop.java
├── 5_factorial_recursion.java
├── 6_even_odd_check.java
├── 7_binary_search.java
├── 8_bubble_sort.java
├── 9_insertion_sort.java
├── 10_palindrome_check.java
└── README.md

Every file is focused on one problem, and has: - Terminal-compatible code - Meaningful variable names - Comments for explanation - No boilerplate distractions ---

🧪 How to Run Java Files from This Repo

Each file can be compiled and run via command line:

javac 3_reverse_integer.java
java reverse_integer

Make sure: - Class name matches file name - No `public` keyword used (unless filename = class name) ---

🎯 Why This Helps in Interviews

Most service-based and product-based companies ask logic-based Java questions. This repository helps in:

• 🧠 Building confidence in core Java
• 💻 Practicing logic in terminal/VS Code
• 🎯 Fast recall during interviews
• 📘 Strengthening DSA basics
• ✅ Better time management in test rounds

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🔗 GitHub Repo Link

➡️ Visit the GitHub Project Here ---

📚 What’s Next?

I’m continuously adding more questions around: - String algorithms - Recursion patterns - Sorting techniques - Stack/Queue logic - Java 8 features (Streams, Lambda, Optional) You’re welcome to contribute, fork, or star the repo if it helps you too! ---

💬 Final Words

This project is not just a coding repo, it’s my personal preparation journey made public to help others. If you're preparing for Java-based roles, bookmark this and revisit often. Practice, understand, and crack your dream job. ---

🙌 Let’s Connect!

You can find me on:

• GitHub: github.com/csharma198
• LinkedIn: linkedin.com/in/mrcsharma198

Let me know if this blog helped you in your preparation journey. Best of luck, and keep coding! 🚀