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To: David Rodrigues <david.proweb@gmail.com>,
 PHP Internals <internals@lists.php.net>
References: <CAEsg9X1sq7ieCSTQP+AKmujHLTx+q8Vd_AiYVVGeT4SDF8Kyeg@mail.gmail.com>
Message-ID: <b306c6a9-7121-6df3-1243-99e7b672b534@gmx.de>
Date: Sat, 14 Mar 2020 16:52:42 +0100
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Subject: Re: Argument with default value
From: cmbecker69@gmx.de ("Christoph M. Becker")

On 14.03.2020 at 16:27, David Rodrigues wrote:

> I would like to propose the idea of having a keyword that can be used to
> use the default value of a parameter, without necessarily having to know
> it. Since PHP is not a strong typing language, the default values they u=
se
> are quite mixed, and it is difficult to predict each without knowing the
> documentation (if you have documented it) or using IDE support.
>
> public function __construct($data =3D []);
> public function __construct($data =3D null);
>
> I always prefer to use null as the default value to optional parameter, =
and
> then define the value transformation in case it is null. But a lot of
> third-party code defines how they want the default value.
>
> String: null or ''
> Array: null or []
> Integer: null or 0
> Boolean: null, true or false
>
> In addition to other values that can actually be used as defaults in a m=
ore
> specific way.
>
> public function test(int $pi =3D M_PI, int $a =3D null, int $b =3D 0)
>
> My suggestion would be to use the keyword "default" in the context of th=
e
> argument. To avoid confusion, another keyword could be created, but I do=
n't
> see why they confuse "default" as an argument and "default" for switch.
>
> test(default, 2) =3D=3D=3D test(M_PI, 2, 0)

FWIW, this has been proposed as RFC[1] quite a while ago, but has been
declined.

[1] <https://wiki.php.net/rfc/skipparams>

=2D-
Christoph M. Becker