const arr = [1,2,3,4,5];
function myItertor(arr) {
let index = 0;
return {
next: function() {
const value = arr[index]
let obj;
if(value) {
obj = {
value: arr[index],
done: false
}
index++
} else {
obj = {
value: undefined,
done: true
}
}
return obj
}
}
}
const a = myItertor(arr);
console.log(a.next());
console.log(a.next());
console.log(a.next());
console.log(a.next());
console.log(a.next());
console.log(a.next());
const b = arr[Symbol.iterator]()
console.log(b.next())
console.log(b.next())
console.log(b.next())
console.log(b.next())
console.log(b.next())
console.log(b.next())