EcmaScript | ES6 generators.js

function* generateSequence(start, end) {
  for (let i = start; i <= end; i++) yield i
}

const sequence1 = generateSequence(1, 10)

for (const n of sequence1) {
  console.log(n) // Expected output: sequence from 1 to 10
}

const sequence2 = generateSequence(1, 3)
console.log(sequence2.next().value) // Expected output: 1
console.log(sequence2.next().value) // Expected output: 2
console.log(sequence2.next().value) // Expected output: 3
console.log(sequence2.next().done) // Expected output: true

const abcCodes = generateSequence(65, 90)

for (const code of abcCodes) {
  console.log(String.fromCharCode(code)) // Expected output: ABC from A to Z
}