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Date: Sun, 19 May 2024 01:30:08 -0700
Message-ID: <CAPrKfG489yey-ZCMT7J8GkiZ13oqY1e2rPwuMk35A0+FhRG_-Q@mail.gmail.com>
Subject: [PHP-DEV] [Discussion] Why can't I do "{$a::class}"?
To: internals@lists.php.net
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From: sarkedev@gmail.com (Peter Stalman)

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Hi Internals,

Obviously we can't use constants or functions directly in strings using
variable parsing, I assume because it lacks the easily detectable $.

However, we _can_ use methods because the object variable has the $, which
I assume is the reason methods work and functions don't.

I feel like it's something that _could_ have been added when dynamic access
of static members support was added in 5.3.0, but maybe it was overlooked
or decided against?  Consider:

```
<?php

$a = new A();

echo " {A::$static_property} \n"; // doesn't work (unless $static_property
is a variable)
echo " {$a::$static_property} \n"; // works

echo " {A::static_method()} \n"; // doesn't work (just text)
echo " {$a::static_method()} \n"; // works

echo " {A::constant} \n"; // doesn't work
echo " {$a::constant} \n"; // doesn't work either, but why?

?>
```


Also, as a side note, why does this hack below work?  It seems like
something that would use `eval()`, but doesn't.  Take a look:

https://3v4l.org/aPCSD

I found it at the bottom of the manual entry for Strings[1].  Not something
I would use, but it's interesting to see.

Thanks,
Peter

[1]: https://www.php.net/manual/en/language.types.string.php#91628

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<div dir=3D"ltr">Hi Internals,<div><br></div><div>Obviously=C2=A0we can&#39=
;t use constants or functions directly in strings using variable parsing, I=
 assume because it lacks the easily detectable $.</div><div><br></div><div>=
However, we _can_ use methods because the object variable has the $, which =
I assume is the reason methods work and functions don&#39;t.</div><div><br>=
</div><div>I feel like it&#39;s something that _could_ have been added when=
 dynamic access of static members support was added in 5.3.0, but maybe it =
was overlooked or decided against?=C2=A0 Consider:</div><div><br></div><div=
>```</div><div>&lt;?php</div><div><br></div><div>$a =3D new A();<br><br>ech=
o &quot; {A::$static_property} \n&quot;; // doesn&#39;t work (unless $stati=
c_property is a variable)<br>echo &quot; {$a::$static_property} \n&quot;; /=
/ works<br><br>echo &quot; {A::static_method()} \n&quot;; // doesn&#39;t wo=
rk (just text)<br>echo &quot; {$a::static_method()} \n&quot;; // works<br><=
br>echo &quot; {A::constant} \n&quot;; // doesn&#39;t work<br>echo &quot; {=
$a::constant} \n&quot;; // doesn&#39;t work either, but why?<br></div><div>=
<br></div><div>?&gt;</div><div>```</div><div><br></div><div><br></div><div>=
Also, as a side note, why does this hack below work?=C2=A0 It seems like so=
mething that would use `eval()`, but doesn&#39;t.=C2=A0 Take a look:</div><=
div><br></div><div><a href=3D"https://3v4l.org/aPCSD">https://3v4l.org/aPCS=
D</a><br></div><div><br></div><div>I found it at the bottom of the manual e=
ntry for Strings[1].=C2=A0 Not something I would use, but it&#39;s interest=
ing to see.</div><div><br></div><div>Thanks,</div><div>Peter</div><div><br>=
</div><div>[1]:=C2=A0<a href=3D"https://www.php.net/manual/en/language.type=
s.string.php#91628">https://www.php.net/manual/en/language.types.string.php=
#91628</a></div></div>

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