const letters = ["a", "b", "c"];
const iterator = letters[Symbol.iterator]();
iterator.next();
iterator.next();
// Result:
// {done: false, value: 'b'}
const letters = ["a", "b", "c"];
const iterator = letters[Symbol.iterator]();
iterator.next();
iterator.next();
// Result:
// {done: false, value: 'b'}