The goal today is to write a function that returns the sum of all prime numbers up to a limit. We will do this in two steps: first we're going to write an isPrime function that checks wether or not a number is prime, and then the actual sumPrimes function.

Check if a number is prime

Write an isPrime function that takes a number as parameter and returns true if this number is prime, false if it isn't.

Reminder: A prime number:

Can only be divided by 1 and itself

Is greater than 1

Sum all primes

Write a sumPrimes function to sum all prime numbers up to the parameter limitincluded. Copy you isPrime function from the last assignment to make use of it here.

Create your playground on Tech.io

This playground was created on Tech.io, our hands-on, knowledge-sharing platform for developers.