Idea of range in js

range.js

function* rangeG(length) {
  let cnt = -1
  while (cnt < length - 1) yield ++cnt
}

function range(length) {
  return [...rangeG(length)]
}

console.log(range(0))   // []
console.log(range(10))  // [0, 1, ..., 9]

console.log('-------------------------')

function range2(length) {
  return [...Array(length).keys()]
}

console.log(range2(0))   // []
console.log(range2(10))  // [0, 1, ..., 9]