A map is a collections of key-value pairs. Each key must be unique, and uniqueness is determined by (roughly) === comparison.

    Unlike objects, keys can be any value, not just strings and symbols.

    The main APIs are:

    • set
    • get
    • has
    • delete

    It's still much more common to use objects than maps

    Creating maps

    Working with maps

    When working with maps, we commonly convert them to and from arrays, since arrays have more built-in methods for transforming the contents.

    This array of "tuples" is the same as what Object.entries returns for objects