range.js

function range(start, stop, step = 1) {
  if (Math.sign(stop-start) !== Math.sign(step) || step === 0) {
    return [];
  }

  let nums = [];

  if (step > 0) {
    for (let i = start; i <= stop; i += step) {
      nums.push(i);
    }
  } else {
    for (let i = start; i >= stop; i += step) {
      nums.push(i);
    }
  }

  return nums;
}