Balwa Group Interview Questions and Answers

Regex for email validation

• Start with a string of characters followed by @ symbol

• Followed by a string of characters and a period

• End with a string of characters with a length of 2-6 characters

• Allow for optional subdomains separated by periods

• Disallow special characters except for . and _ in username

Print prime numbers in a given range and optimize the solution.

• Use Sieve of Eratosthenes algorithm to generate prime numbers efficiently

• Start with a boolean array of size n+1, mark all as true

• Loop through the array and mark all multiples of each prime as false

• Print all the indexes that are still marked as true

Find angle between hour and minute hand in a clock given the time.

• Calculate the angle made by the hour hand with respect to 12 o'clock position

• Calculate the angle made by the minute hand with respect to 12 o'clock position

• Find the difference between the two angles and take the absolute value

• If the angle is greater than 180 degrees, subtract it from 360 degrees to get the smaller angle

To un-hash a string, use a reverse algorithm to convert the hash back to the original string.

• Create a reverse algorithm that takes the hash as input and outputs the original string

• Use the same logic as the hash function but in reverse order

• If the hash function used a specific algorithm, use the inverse of that algorithm to un-hash the string

I am proficient in Java, Python, and C++. I have 2 years of experience in software development. I have excellent communication skills for client interaction.

• Proficient in Java, Python, and C++

• 2 years of software development experience

• Excellent communication skills for client interaction

Event loop is a mechanism that allows non-blocking I/O operations in a single-threaded environment.

• Event loop is used in programming languages like JavaScript and Python.

• It manages the execution of multiple tasks by prioritizing them based on their priority level.

• It continuously checks for new events and executes them in a loop.

• It allows for efficient handling of I/O operations without blocking the main thread.

• It is co...read more

let, var and const are used to declare variables in JavaScript with different scoping rules and mutability.

• let and var are used to declare variables that can be reassigned later, but var has function scope while let has block scope.

• const is used to declare variables that cannot be reassigned and have block scope.

• Using const does not mean the value is immutable, only the variable reference is.

• let and const were introduc...read more