Iterators know how to access items from a collection one at a time, while keeping track of its
current position within that sequence. In JavaScript an iterator is an object that provides a
next() method which returns the next item in the sequence. This method returns an object with two
properties: done and value. More reading: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Iterators_and_Generators
const makeIterator = (array) => {
let index = 0
return {
next: () => {
if (index < array.length) {
return {
value: array[index++],
done: false
}
} else {
return { done: true }
}
}
}
}
const myArray = ["yo", "ya"]
const iterator = makeIterator(myArray)
console.log(iterator.next().value) // yo
console.log(iterator.next().value) // ya
console.log(iterator.next().done) // true