Clean Code in JavaScript

Iterable protocol

The iterable protocol allows values containing sequences to share a common set of characteristics, allowing them to all be iterated over or treated in a similar way.

We can say that an object that implements the iterable protocol is iterable. Iterable objects within JavaScript include Array, Map, Set, and String.

Any object can define its own iterable protocol by simply supplying an iterator function under the property name's Symbol.iterator (which maps to the internal @@iterator property).

This iterator function must fulfill the iterator protocol by returning an object with a next function. This next function, when called, must return an object with done and value keys indicating what the current value of the iteration ...