JSFiddle - React, Tailwind, and code Playground

by ronilan

HTML

// Find the sum of all the prime numbers below two million.
// A prime number is any number only divisible by 1 and itself (except 1).
// The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.

JavaScript

// Find the sum of all the prime numbers below two million.
// A prime number is any number only divisible by 1 and itself (except 1).
// The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.

sumPrime = function (toWhere) {

    var i,
        j,
        isPrime = true,
        result = [2],
        sum = 0;

    for (i = 2; i <= toWhere; i++) {

        j = result.length;

        while (j--) {
            // devisable
            if (i % result[j] === 0) {
                isPrime = false;
                break;
            }

        }

        if (isPrime) {
            result.push(i);
        }

        isPrime = true;

    }

    j = result.length;
    while (j--) {
        sum = sum + result[j];
    }

    return sum;

}

console.log(sumPrime(2000));