Boolean() vs !!

[rahulpatel]

As the title says. Add your reaction to the one you prefer and drop a comment if you wish to give a reasoning.

[rahulpatel]

Boolean()

[rahulpatel]

!!

[pmcnr-hx]

I'll take the opportunity to add the other very common case (convert a numerical string to an integer): /1 (or any or its variants) vs parseInt(..., 10).

[pmcnr-hx]

/1 or +0 or any of the other similar variants

[pmcnr-hx]

parseInt(..., 10)

[jamesmcneil]

Prefer Boolean over !! as this is more easily understandable to a new starter reading our codebase for the first time. (Clarity over Brevity)

[Nick-Patrick]

I personally find !! very unreadable and looks slightly hacky. Most of us know what it means but not everyone.

Compare !!someAray to Boolean(someArray).

The difference with Boolean(something) - it's instantly readable and obvious to what it's doing.

[jameshhx]

👍 for Boolean. It's completely clear what is happening. You could argue that it's pretty clear what !! does, but for readability and clarity, Boolean is the right choice.

[pmcnr-hx]

clarity > brevity

[dancork]

For serverside code this makes sense but clientside code where bytes matter then !! and +0 gets my vote.

[Arditc]

From looking at another culture repository (airbnb) https://github.com/airbnb/javascript#coercion--booleans
It seems they're happy either. So think this is more personal preference.

[pmcnr-hx]

Don't JS compressors take care of that kind of thing for you @dancork?

[dancork]

I thought compressors/minifiers only touched arguments and scoped vars and functions.

[pmcnr-hx]

That's probably true @dancork. I am not an expert, hence the question. UglifyJS doesn't seem to do it. However, this seemed such an obvious thing that could be automated, instead of having humans worrying about it, that I couldn't believe someone hadn't done it. The Google Closure Compiler seems to do exactly that:

var x = 0;
console.log(Boolean(x));

after running through the closure command becomes:

var x=0;console.log(!!x);

So I would argue there are options, even for the smallest possible payloads in the front-end, that don't sacrifice readability, and allow us to have a consistent coding style everywhere.
Out of curiosity, is there a reason why we are not using it?

[dancork]

That's a good shout @pmcnr-hx maybe one for a project lounge :)