+1 from me for !in. It's a surprisingly common nuisance.
And I don't care for the !obj.x workaround at all -- even if you can
survive the difference in semantics, from a code reading point of view
this is saying something entirely different.
And it is very different semantically. 'x' in obj does [[HasProperty]];
obj.x does [[GetProperty]]. With
obj = { get x() { print("getter"); return 3; } };
then |"x" in obj| does not print "getter" while |obj.x| does.
On 06/29/2018 12:26 AM, Cyril Auburtin wrote:
```js
if (!obj.x && !obj.y) {
doit()
}
```
The cases where they are equal to 0, '', null, undefined shouldn't
matter imo, if for example those x and y are numbers, they would be
defined, defaulted to 0, and you would test for `!== 0` rather if needed
Le jeu. 28 juin 2018 à 18:31, Guylian Cox <[email protected]
<mailto:[email protected]>> a écrit :
I agree, it's very annoying to have to write it !(x in y). I've
been wanting this operator for a very, very long time.
If there is interest for !in, I think !instanceof deserves to be
included too.
Le jeu. 28 juin 2018 à 18:19, T.J. Crowder
<[email protected]
<mailto:[email protected]>> a écrit :
On Thu, Jun 28, 2018 at 5:14 PM, Tobias Buschor
<[email protected] <mailto:[email protected]>>
wrote:
> I dont like to write:
> if ( !('x' in obj) && !('y' in obj) ) {
> doit()
> }
>
> I was even tempted to write it that way:
> if ('x' in obj || 'y' in obj) { } else {
> doit()
> }
There's
```js
if (!('x' in obj || 'y' in obj)) {
doit()
}
```
That said, I've wanted !in many a time, in a minor sort of way...
-- T.J. Crowder
_______________________________________________
es-discuss mailing list
[email protected] <mailto:[email protected]>
https://mail.mozilla.org/listinfo/es-discuss
_______________________________________________
es-discuss mailing list
[email protected] <mailto:[email protected]>
https://mail.mozilla.org/listinfo/es-discuss
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
