Feature Request: Number.isNumber()

Álex Puchades alex94puchades at gmail.com
Sun Apr 10 16:54:50 UTC 2016


El 10/4/2016 5:08 PM, "Adrian Sieber" <adrian.sieber1 at gmail.com> escribió:
>
> Hi everybody,
>
> checking if a value is a number is currently really complicated and
> I have stumbled upon a fair amount of code where this lead to bugs.
>
> The easiest way is `typeof value === 'number'`.

What about Number.isFinite?

> This however has the drawback that `NaN` also evaluates to true.

Number.isFinite(NaN) is `false`

> Furthermore, basically every expression preceded by a `+` evaluates to
true.
> … and there are even more gotchas. For a full roundup read
https://github.com/jonschlinkert/is-number.
>
> This implementation could also be used as a starting point.
> (However, I would argue that `isNumber('3')` should evaluate to false.
> It's a string after all.)
>
> Therefore I think a `isNumber` functionality should already be provided
natively.
> What do you think?
>
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