Generate fibonacci sequence

fibonacci.js

/**
 * Generate fibonacci sequence up to `maxNum`
 * https://en.wikipedia.org/wiki/Fibonacci_number
 *
 * @param {number} maxNum
 */
function fibonacci (maxNum) {
  const result = [0, 1]
  let newNum, index

  for (index = 2;;index++) {
    newNum = result[index - 2] + result[index - 1]

    if (newNum <= maxNum) {
      result.push(newNum)
    } else {
      break
    }
  }

  return result
}