Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Focus : JavaScript Logical Puzzles & Debugging

Challenge :

Write a JavaScript function that returns the intersection of two arrays without using built-in filter() or Set.

Debugging Puzzle :

function reverseStr(str) {
  return str.split().reverse().join();
}
console.log(reverseStr("hello"));

Fix the bug so that it correctly reverses "hello" → "olleh".

Playground :CodePen / JSFiddle

Backend Challenge

|Focus : C, C++, C#

C Challenge :

• Write a program to find the second largest element in an array without sorting.

C++ Challenge :

• Implement a stack using two queues.

C# Challenge :

• Write a C# program to connect to a SQL Server database and fetch all records from an Employees table."

Database Query Challenge

Problems on SQL - HR Database :

1. Write a query to display employees whose salary is above the average salary of their department.
2. Write a query to list the top 2 highest-paid employees in each job role

Data Structures & Algorithms Challenge

• Easy:
• Problem :Find the maximum sum subarray of size k.
• Hint :Use the sliding window technique.
• Medium:
• Problem : Implement a min stack (stack that supports retrieving the minimum element in O(1) time).
• Hint :Use an auxiliary stack or track min with each push.
• Hard:
• Problem :Given a graph, detect if it has a cycle (directed graph).
• Hint :Use DFS with recursion stack or Kahn’s algorithm.

Bug of the Day

Focus : C, C++, C#

Buggy Code ( C ):

#include 
int main() {
    int arr[5] = {1,2,3,4,5};
    for(int i = 0; i <= 5; i++) {
        printf("%d ", arr[i]);
    }
    return 0;
}

Find & Fix : What’s wrong?

📋 Daily Micro-Project

Focus : Frontend

Task :

Build a real-time character counter for a text area.

• Show remaining characters (limit 200).
• If limit exceeds, show warning in red.

Trivia: 5 Fun Facts

1. The first computer programmer was Ada Lovelace in the 1800s.
2. The original name of Java was Oak.
3. C language was created at Bell Labs by Dennis Ritchie in 1972.
4. GitHub was launched in 2008, now hosts 100M+ repos.
5. The “Hello, World!” program originated in C tutorials by Brian Kernighan.

Tool & Resource of the Day

Tool : Visual Studio Code

• Lightweight, cross-platform IDE with extensions.
• Perfect for JavaScript, Python, C++, and full-stack development.

Resource Roundup :

• FreeCodeCamp’s JavaScript Handbook
• GeeksforGeeks C Programming Practice
• Microsoft Docs for C#

Interview Question of the Day

Daily Interview Questions

Frontend :
1. Difference between == and === in JavaScript?
2. How does JavaScript handle asynchronous code (event loop)?
3. Explain this keyword in different contexts.
4. What are React keys, and why are they important?

Backend :
1. Explain memory leaks in C.
2. What is the difference between struct and class in C++?
3. How does garbage collection work in C#?
4. Explain multi-threading in C#.

Database :
1. What is a foreign key?
2. Difference between primary key and unique key?
3. Explain normalization and its types.

Others :
1. What is an operating system kernel?
2. Explain virtualization vs containerization.

Daily Quiz Challenge

Frontend :

1. What is the output of console.log([] + []);
2. In React, which hook is used for managing side effects?
3. Which CSS property controls text size?

Backend :

1. In C, malloc() returns:
2. Which operator is overloaded by cout in C++?
3. In C#, what does async keyword indicate?

Mixed :

1. Database : SQL keyword used to sort results
2. Other :Who created the C programming language?

Weekly Cross-Domain Activities ( August 22 to August 28, 2025 )

API of the Day:

Build a Weather App using OpenWeatherMap API.

Linux Tip :Use htop to monitor CPU, memory, and processes in real-time.

Real-World Project of the Week ( August 22 to August 28, 2025 )

Project of the Week:

Build a Personal Portfolio Website with HTML, CSS, and JavaScript.

Collaborative Project :

Create an Open Source Expense Tracker in React + Node.js.

Case Study :

Analyze Twitter’s infinite scrolling → implement it using React + Intersection Observer API.