freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/sum-all-odd-fibonacci-numbers.md

id	title	challengeType	forumTopicId	dashedName
a5229172f011153519423690	Sum All Odd Fibonacci Numbers	5	16084	sum-all-odd-fibonacci-numbers

--description--

Given a positive integer num, return the sum of all odd Fibonacci numbers that are less than or equal to num.

The first two numbers in the Fibonacci sequence are 1 and 1. Every additional number in the sequence is the sum of the two previous numbers. The first six numbers of the Fibonacci sequence are 1, 1, 2, 3, 5 and 8.

For example, sumFibs(10) should return 10 because all odd Fibonacci numbers less than or equal to 10 are 1, 1, 3, and 5.

--hints--

sumFibs(1) should return a number.

assert(typeof sumFibs(1) === 'number');

sumFibs(1000) should return 1785.

assert(sumFibs(1000) === 1785);

sumFibs(4000000) should return 4613732.

assert(sumFibs(4000000) === 4613732);

sumFibs(4) should return 5.

assert(sumFibs(4) === 5);

sumFibs(75024) should return 60696.

assert(sumFibs(75024) === 60696);

sumFibs(75025) should return 135721.

assert(sumFibs(75025) === 135721);

--seed--

--seed-contents--

function sumFibs(num) {
  return num;
}

sumFibs(4);

--solutions--

function sumFibs(num) {
  var a = 1;
  var b = 1;
  var s = 0;
  while (a <= num) {
    if (a % 2 !== 0) {
      s += a;
    }
    a = [b, b=b+a][0];
  }
  return s;
}