Newbie: How to create a Javascript map?

Hi - I'm afraid there's no Map object built into Espruino.

But what do you actually want to use it for? By default objects work basically the same way...

a = {};
a["foo"] = 42; // put
console.log(a["foo"]); // get
console.log("foo" in a); // check if inside
delete a["foo"] // remove
// ...