Iterables

From Iteration protocols:

String, Array, TypedArray, Map, and Set are all built-in iterables, because each of their prototype objects implements an @@iterator method.

Make an iterator

const myIterable = {};

myIterable[Symbol.iterator] = function* () {
    yield 1;
    yield 2;
    yield 3;
};

console.log([...myIterable]); // [1, 2, 3]