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To: internals@lists.php.net Content-Type: multipart/alternative; boundary="00000000000024c5b10636b6cbb2" From: bradley.hayes@tithe.ly (Bradley Hayes) --00000000000024c5b10636b6cbb2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Could be handy to allow this in normal functions too (but this it not the main use case and could be disallowed): public static function get(string $name, mixed $default =3D uninitialized):= string { $value =3D getenv($name); if ($value =3D=3D=3D false) { return $default; // throws uninitialized error. } return $value; } Not specifying a default value can now be done without creating a class or 'some highly specific string to avoid conflicts' to check for it just throws an error when it cant return a value. However, the uninitialized error is too generic for this situation and youd want a more specific error message. This would naturally make you think to check for uninitialized instead of using a try->catch block. To avoid treating it as a type of value with =3D=3D=3D a helper function could be provided changing the function like so: public static function get(string $name, mixed $default =3D uninitialized):= string { $value =3D getenv($name); if ($value =3D=3D=3D false) { if (isInitialized($default)) return $default; throw new \Exception("Environment variable '$name' not found."); } return $value; } On Tue, Jun 3, 2025 at 2:22=E2=80=AFPM Bradley Hayes wrote: > Uninitialized properties are really useful. > Being skipped in foreach loops and JSON encoded results and other > behaviours around uninitialized properties save a lot of time wasted on > basic checks and uncaught logical mistakes around null values. > > With the introduction of named arguments and promoted constructor > properties and read-only classes, it would be great to have the true > ability to not specify a value. > > class DTO { > public function __construct( > public string $id =3D uninitialized, > public string $name =3D uninitialized, > public null|int $age =3D uninitialized, > ) {} > } > > $dto =3D new DTO(id: 'someid', age: null); > if ($dto->age =3D=3D=3D null) echo "no age was given\n"; > echo $dto->name, PHP_EOL; // triggers the standard access before initial= isation error > > > EXAMPLE: A graphQL like API that only returns data that was asked for, is > serviced by a PHP class that only fetched the data that was asked for and > thus the DTO only has assigned values if they were fetched. > (These situations usually way more complex involving multiple SQL > joins/filters etc and nested objects/arrays in the return DTO). > > The DTO object has all the possible values defined on the class for type > safety and IDE indexing, but allows the uninitialized error to happen if > you try to use data that was never requested. > Uninitialized Errors when directly accessing a property that was not > assigned is also desirable as it indicates a logical error instead of > thinking the value is null. Null is considered a real value in the databa= se > in countless situations and API can assign null to delete a value from an > object. > > Additionally, since array unpacking now directly maps to named arguments = this would also save a ton of mapping code. > > *//array unpacking direct from the source > *$dto =3D new DTO( ...$sqlData); > > (FYI: SQL is way faster at mapping thousands of values to the naming > convention of the class than doing it in php so we do it in SQL. So yes w= e > would directly array unpack an sql result here.) > > I have is a discussion on this in github here: > https://github.com/php/php-src/issues/17771 > > The current workaround is to make the constructor take an array as its > only parameter and looping over it assigning matching array key values to > class properties and ignoring the rest. > > This works but breaks indexing and prevents the use of class inheritance > because not all the properties can be seen from the same scope forcing > every extender of the class to copy paste the constructor code from the > parent class. > > > -- > > Bradley Hayes / Engineer / TITHE.LY > > > > --=20 Bradley Hayes / Engineer / TITHE.LY --00000000000024c5b10636b6cbb2 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 
Could be handy to allow this =
in normal functions too (but this it not the main use case and could be dis=
allowed):
public static function =
get(string $name, m=
ixed $default =3D uninitialized): string
{
    $value =3D getenv($name);
    if ($value =3D=3D=3D false) {
        return $default; // throws uninitialized error.
    }
    return =
$value;
}

Not specifying a default value can now be done without creating a class or =
'some highly specific string to avoid conflicts' to check for it ju=
st throws an error when it cant return a value.
However, the uninitialized error is too generic for this situ=
ation and youd want a more specific error message.
This would naturally make you think to check for uniniti=
alized instead of using a try->catch block.
To avoid treating it as a type of value with =3D=3D=3D a helpe=
r function could be provided changing the function like so:
public static func=
tion get<=
font color=3D"#000000" style=3D"font-size:9.8pt">(string $name, mixed $defau=
lt =3D uniniti=
alized): string
{
    $value =3D getenv=
($name);
    if (=
$value =3D=3D=3D false) {
        if =
(isInitialized($default)) return $default;
        throw new \Exception("Environment variable '$name' not found.");<=
/span>
    }
    return $value;
<=
/span>}

On Tue, Jun 3, 2025 at 2:22=E2=80= =AFPM Bradley Hayes <bradley.h= ayes@tithe.ly> wrote:
Uninitialized properties are really= useful.
Being skipped in foreach loops and JSON encoded results = and other behaviours around uninitialized properties save a lot of time was= ted on basic checks and uncaught logical mistakes around null values.
=

With the introduction of named arguments and promoted c= onstructor properties and read-only classes, it would be great to have=C2= =A0the true ability to not specify a value.
class DTO {
    =
public function __construct(
        public string $id =3D uninitialized,
        public string $name =3D uninitialized,
        publi=
c null|int $age =3D uninitialized,
    ) {}
}

$dto =3D new DTO(id: 'some=
id', age: null);
if ($dto->age =3D=3D=3D null) echo "no age was given\n"=
;;
echo  $dto->name, PHP=
_EOL; // tr=
iggers the standard access before initialisation error

EXAMPLE: A graphQL like API that only returns= data that was asked for, is serviced by a PHP class that only fetched the = data that was asked for and thus the DTO only has assigned values if they w= ere fetched.
(These situations usually way more complex involving= multiple=C2=A0SQL joins/filters etc and nested objects/arrays in the retur= n DTO).

The DTO object has all the possible values= defined on the class for type safety and IDE indexing, but allows the unin= itialized error to happen if you try to use data that was never requested.<= /div>
Uninitialized Errors when directly accessing a property that= was not assigned is also desirable as it indicates a logical error instead= of thinking the value is null. Null is considered a real value in the data= base in countless situations and API can assign null to delete a value from= an object.
Additionally, since array unpacking now directly maps to named argum=
ents this would also save a ton of mapping code.
<= div>
//array unpacking direct from=
 the source
$dto =3D new DTO( ...$sqlData);<=
/pre>
(FYI: SQL is way faster at mapping thousa= nds of values to the naming convention of the class than doing it in php so= we do it in SQL. So yes we would directly array unpack an sql result here.= )

I have is a discussion on this in github here:

The current workaround is to make the constructor take an array as it= s only parameter and looping over it assigning matching array key values to= class properties and ignoring the rest.

This work= s but breaks indexing and prevents the use of class inheritance because not= all the properties can be seen from the same scope forcing every extender = of the class to copy paste the constructor code from the parent class.


<= span class=3D"gmail_signature_prefix">--

Bradley= Hayes / Engineer / TITHE.LY


<= /span>


--
--00000000000024c5b10636b6cbb2--