New JavaScript Set Methods

Maybe one self-contained example w/ a new function you can copy/paste into the console to play around with would be cool.

I was mostly using it as a test to see if it worked in Chrome so I could start using it.

0: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

1: https://docs.oracle.com/javase/8/docs/api/java/util/LinkedHa...

Because we are not adding elements in the middle of the list, only the end (we only care about insertion order), `add` is still O(1). `has` searches on the HashSet so it is also O(1). Delete is a bit more complex, you need to keep the list node reference on the set node, and then just splice it from the list. So O(1) as well

Of course this takes a lot more memory, but I think it usually pays off to have consistent ordering for sets, undefined/non-deterministic behavior is a virus and it spreads very quickly

Maybe we'll see it one day.

`[6,-2,2,-7].sort( (a,b) => a-b)`

Result: Int32Array [-7, -2, 2, 7] (4)

The problem is you can put anything in array and JS can't really check that "everything here is a number", so it uses string as a common type because everything can be converted to string.

we need proper typed arrays, like Int8/16/32Array but with any class, not just int. The class itself will then define how to compare instances (python's __gt__ and so on).

    const x = {};
    ‘constructor’ in x // true
    x[‘constructor’] === Object // true

Some properties cannot be deleted, and some cannot be modified:

    delete x.constructor;
    x.constructor === undefined // false
    x.__proto__ = undefined;
    x.__proto__ === undefined // false

It's O(1) for the latter (edit: I stand corrected, but probably close, as per spec).

Conversion to and from arrays even preserves order.

So I don't see these two use cases as "showing off", why should anybody do that?

    const s = new Set();

    const a = {}, b = {};

    s.add(a);

    s.has(a); // true

    s.has(b); // false


    const o = {};

    o[a] = true;

    o[a]; // true

    o[b]; // true, cause its cast to a string like "[object Object]"