Daily Coding Challenges & Projects

Frontend Mini Project Challenge

Focus : JavaScript Logical Puzzles + JavaScript Debugging

Challenge 1 – JavaScript Logical Puzzle :

Write a JavaScript function that checks whether two strings are anagrams of each other.

Find and fix the bug in the code below:

• Ignore spaces and letter case
• Do not use built-in sorting methods

Challenge 2 – JavaScript Debugging :

Conditions :

function sum(arr) {
  let total = 0;
  arr.forEach(num => {
    total = total + num;
  });
  return;
}
console.log(sum([1, 2, 3, 4]));

Task :

• Identify why the function does not return the expected output
• Fix the issue without changing the loop logic

Backend Challenge

Language Focus : C, C++, C#

Scala Challenge :

Problem Statement : Implement a program that checks whether a given number is a power of 2.

Requirements :

• Input: An integer
• Output: True or False
• Do not use logarithmic functions

Bonus :

• Solve using bitwise operators

Database Query Challenge

Problems on SQL - HR Database :

1. Write an SQL query to find employees whose job title has not changed since joining the company.
2. Write an SQL query to list departments where average salary is greater than the company-wide average salary.

Data Structures & Algorithms Challenge

• Easy :
• Problem : Check if an array is sorted in non-decreasing order.
• Hint : Compare each element with the next one.
• Medium :
• Problem : Find the first non-repeating character in a string.
• Hint : Use a frequency map and preserve order.
• Hard :
• Problem : Given an array, find the length of the longest subarray with sum equal to zero.
• Hint : Use prefix sum and hashing.

Bug of the Day

Language Focus : C

Buggy Code ( C ) :

#include 

int main() {
    int i;
    for (i = 0; i <= 5; i++);
    {
        printf("%d ", i);
    }
    return 0;
}

Challenge :

• Identify the logical error
• Explain why the loop does not work as expected
• Fix the code

📋 Daily Micro-Project

Focus : Frontend

Task : Build a JavaScript-based counter app

Requirements : Persist to local file.

• Increment button
• Decrement button
• Reset button
• Prevent counter from going below zero

Time Limit : 30 minutes

Trivia: 5 Fun Facts

1. The C programming language was created by Dennis Ritchie in 1972.
2. JavaScript was created in just 10 days.
3. The first computer bug was an actual moth.
4. Linux was first released in 1991.
5. The original name of Java was "Oak".

Tool & Resource of the Day

Tool : ESLint

• Helps detect JavaScript errors
• Enforces coding standards
• Improves code quality

Resource Roundup :

• Free JavaScript debugging guide
• ESLint rule reference
• JavaScript logical problem practice links

Interview Question of the Day

Daily Interview Questions

Frontend :
1. What is the difference between var, let, and const?
2. What is hoisting in JavaScript?
3. Explain closures with an example.
4. What is event bubbling?

Backend :
1. What is the difference between stack and heap memory?
2. Explain pointers in C.
3. What is the difference between compilation and interpretation?
4. How does garbage collection work in managed languages?

Database :
1. What is normalization?
2. What is the difference between DELETE and TRUNCATE?
3. What is a primary key?

Others :
1. What is a deadlock?
2. What is an operating system scheduler?

Daily Quiz Challenge

Frontend :

1. What will typeof null return in JavaScript?
2. Which method converts JSON to a JavaScript object?
3. What is the default behavior of event.preventDefault()?

Backend :

1. Which operator is used for bitwise AND in C?
2. What is the size of int in C (platform dependent)?
3. What is a memory leak?

Others :

1. Which SQL clause is used to filter rows?
2. What does HTTP status code 404 mean?

Mixed Quiz :

1. Identify the output of a JavaScript closure-based code snippet.

Weekly Cross-Domain Activities ( December 13 to December 18, 2025 )

API of the Day:

Build a crypto price viewer using the CoinGecko API.

• Must auto-refresh prices
• Sort by top gainers

Linux / DevOps Tip :

5 commands to monitor server health :

• free -h
• vmstat
• top
• htop
• sar -r

Real-World Project of the Week ( December 13 to December 18, 2025 )

Project of the Week:

Build a Job Search Aggregator using public APIs + frontend filters

Collaborative Project :

Contribute to an open-source Vue UI library (e.g., Element Plus).

Case Study :

Break down how Notion uses virtual rendering to handle huge documents smoothly.