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Date: Mon, 30 Oct 2023 16:35:37 +0100
Message-ID: <CANS-=pfOF_8-_mOs4mMMtqa+4iCx6m1Cau6boD-ty55qJzOtJQ@mail.gmail.com>
To: tag Knife <fenniclog@gmail.com>
Cc: Marcos Marcolin <marcolindev@gmail.com>, internals@lists.php.net
Content-Type: multipart/alternative; boundary="000000000000c130c60608f0cbfd"
Subject: Re: [PHP-DEV] New RFC : empty() function
From: kjarli@gmail.com (Lynn)

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On Mon, Oct 30, 2023 at 4:21=E2=80=AFPM tag Knife <fenniclog@gmail.com> wro=
te:

> >
> > However, according to my example, the variable is defined and has its
> > value as 0 or false, and empty() returns true anyway. I confess that
> > I've had some problems like this, and we chose not to use empty(), as
> > sometimes 0 or false makes sense as a valid value.
> >
>
> That is exactly as the documentation explains it.
> empty is to check if a variable is not holding a usable value.
> 0, false, true are all valid values and show the variable is not
> empty.
>
> The purpose for empty is to check for undefined variables, empty
> arrays or empty strings.
> eg. "", [], null or undefined.
>

This is exactly where the problem lies. Is a string with just whitespace
empty? Why would an ArrayObject with count 0 not be considered to be empty
while an array with count 0 is? "empty" is subjective and therefore not a
reliable function to use. Especially in legacy code I find that people use
`empty` where they should've been using `count() =3D=3D=3D 0` and have resu=
lted
in bugs that weren't discovered until months or years later. The variations
of `$a =3D=3D=3D ''`, `count($a) =3D=3D=3D 0`, `! isset($a)`, and `$a =3D=
=3D=3D null` already
check all the scenarios you need, without risking funky bugs due to how the
internal check for "falsy" values works.

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