http://www.freecodecamp.com/minsooshin 's solution for Bonfire: Sum All Primes

bonfire-sum-all-primes.js

// Bonfire: Sum All Primes
// Author: @minsooshin
// Challenge: http://www.freecodecamp.com/challenges/bonfire-sum-all-primes
// Learn to Code at Free Code Camp (www.freecodecamp.com)

function sumPrimes(num) {
  var primes = [2];
  
  function isPrime(n) {
    for (var i = 2; i < n; i++) {
      if ( n % i === 0 ) return false;
    }
    return true;
  }
  
  for ( var i = 3; i <= num; i+=2 ) {
    if (isPrime(i)) primes.push(i);
  }
  
  return primes.reduce(function(sum, curr) {
    return sum + curr;
  });
}

sumPrimes(977);