Summation of primes

The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes below two million.

Comment used to generate the code:

// function that finds the sum of the primes below a given number with the lowest O(n) time complexity

function sumPrimes(num:number):number {

      let sum = 0;

      const sieve = [];

      const primes = [];

      // create a sieve of size num

      for (let i = 0; i < num; i++) {

          sieve[i] = true;

      }

      // mark all multiples of primes as non-primes

      for (let i = 2; i < num; i++) {

          if (sieve[i]) {

              for (let j = i * i; j < num; j += i) {

                  sieve[j] = false;

              }

          }

      }

      // get all primes

      for (let i = 2; i < num; i++) {

          if (sieve[i]) {

              primes.push(i);

          }

      }

      // add all primes to sum

      for (let i = 0; i < primes.length; i++) {

          sum += primes[i];

      }

      return sum;

    }

Thoughts:

this is the second iteration of this solution, as the first was doing the simple number crawling I complained about earlier, but took 10 minutes +