Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Theme : JavaScript Logical Puzzle

Example :

Can you write a function to check whether a string is a palindrome, ignoring case and spaces, without using the built-in .reverse()?

Requirements :

isPalindrome("A man a plan a canal Panama"); // true  
isPalindrome("OpenAI"); // false 

Try this in an interactive coding playground!

Backend Challenge

Language Focus : C, C++, C#

C Language Problem :

Write a C program to reverse a singly linked list without using recursion.

Bonus: Optimize it for O(1) space complexity.

Database Query Challenge

Problems on SQL - HR Database :

1. Write a SQL query to display employees whose department is located in 'London'.
2. Write a SQL query to find employees who were hired more than 5 years ago and have 'Manager' in their job title.

Data Structures & Algorithms Challenge

• Easy:
• Problem : Given an array of integers, find the maximum element.
• Hint : You can solve this with a single pass using a loop.
• Medium:
• Problem : Given a string, check if it's made of two identical halves.

Example: "abab" → true, "abcabc" → true, "abcd" → false

• Hint : Use string slicing.
• Hard:
• Problem : Find the length of the longest substring without repeating characters.

Example: "abcabcbb" → 3 ("abc")

• Hint : Sliding window technique can help.

Bug of the Day

Language Focus :

Language : C

Buggy Code:

#include   
int main() {  
    int a = 5, b = 0;  
    int c = a / b;  
    printf("%d", c);  
    return 0;  
}  

Challenge :

Find and fix the issue.

📋 Daily Micro-Project

Frontend Focus :

Task :

Build a simple tooltip that appears when you hover over a button, using only HTML & CSS.

Trivia: 5 Fun Facts

1. The first computer virus for MS-DOS was called "Brain" (1986).
2. Dennis Ritchie created the C programming language.
3. Tim Berners-Lee invented the World Wide Web in 1989.
4. Git, the version control system, was created by Linus Torvalds.
5. The original name of Java was "Oak".

Tool & Resource of the Day

Tool : Visual Studio Code

Why : A powerful, free source-code editor with excellent language support and extensions.

Resource Roundup :

• VSCode Official Documentation
• Free Extension: Live Server for real-time HTML/CSS preview

Interview Question of the Day

Daily Interview Questions

Frontend :
1. What is the difference between let, const, and var in JavaScript?
2. How does JavaScript handle asynchronous code execution?
3. Explain event bubbling and how to stop it.
4. What are controlled vs uncontrolled components in React?

Backend (C, C++, C#) :
1. What is the difference between struct and class in C++?
2. How does memory management work in C#?
3. What is a segmentation fault in C?
4. Explain the concept of inheritance in C++.

Database ( SQL ) :
1. What is a foreign key in relational databases?
2. How does normalization reduce redundancy?
3. Difference between HAVING and WHERE clause?

Others :
1. What is a compiler vs interpreter?
2. Explain what a race condition is in concurrent programming.

Daily Quiz Challenge

Frontend Quiz ( JavaScript Focus ) :

1. What is the output?

console.log(typeof NaN); 

• "number"
• "NaN"
• "undefined"
• "object"
2. Which method converts a JSON string to an object?
• JSON.parse()
• JSON.stringify()
• JSON.objectify()
• JSON.convert()
3. How do you declare a constant in JavaScript?
• var x = 5;
• let x = 5;
• const x = 5;
• constant x = 5;

Backend Quiz ( C, C++, C# ) :

1. What does malloc() do in C?
• Declares a variable
• Allocates memory dynamically
• Returns array size
• Frees memory
2. Which of these is a valid C++ access specifier?
• private
• hidden
• sealed
• internal
3. What is namespace used for in C#?
• Memory optimization
• Grouping related classes
• Faster execution
• Error handling

Database :

1. Which SQL keyword is used to remove duplicate rows?
• UNIQUE
• DISTINCT
• FILTER
• REMOVE

Mixed Quiz :

1. In which language is console.log() primarily used?
• SQL
• JavaScript
• C++
• Python

Weekly Cross-Domain Activities ( June 27 to July 03, 2025 )

API of the Day:

Task : Build a real-time currency converter using the ExchangeRate API

https://www.exchangerate-api.com/

Linux/DevOps Tip :

Title : Top 5 Log Monitoring Commands: tail, grep, less, journalctl, watch

Real-World Project of the Week ( June 27 to July 03, 2025 )

Project of the Week:

Build a Book Management System with Vue.js + Node.js + PostgreSQL

Collaborative Project:

Contribute to an open-source to-do app with multi-user auth on GitHub.

Case Study:

Explore how Notion uses dynamic blocks and replicate a basic block editor.