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Date: Fri, 23 Oct 2020 19:33:10 +0100
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Subject: Re: [PHP-DEV] Re: Is there any interest for object constructor
 shorthand *just forstdClass*
From: rowan.collins@gmail.com (Rowan Tommins)

On 23/10/2020 16:08, Andreas Bittner wrote:
> Closing I would like to make a short point with regards to the 
> `(object)` cast:
> Both a cast of \stdClass to `(array)` and a cast of arrays to 
> `(object)` are common use cases in (JSON-)API development. It is not 
> unheard of for API signatures to contain certain properties of the 
> JSON response object only if some conditions are met. Currently the 
> best way to achieve this is either by dynamically adding properties to 
> an existing \stdClass object, or by populating an array and `(object)` 
> casting it later. 


I don't follow; is the resulting JSON different if you cast to object, 
or is there some other reason you prefer an object over using an 
associative array directly?


Also, to clarify my earlier comment about stdClass not being necessary 
now we have anonymous classes, I meant it very directly: every time you 
write "new stdClass" you can write "new class {}" instead.

The fact that "(object)$foo" creates an instance of "stdClass" rather 
than an instance of "class{}" is just a historical wart, which can be 
easily replaced:

function array_to_object($arr): object {
     $obj = new class {};
     foreach ( $arr as $key => $value ) {
         $obj->{$key} = $value;
     }
     return $obj;
}


The only difference I'm aware of is that you can no longer use 
"stdClass" as a type constraint, but I'm not sure what value that would 
ever have. Indeed, with anonymous classes you could trivially add a much 
more meaningful type constraint using an empty interface:

instead of:

function getFromDB(...): stdClass {
       $result = new stdClass;
       foreach ( $this->blah()  as $column => $value ) {
             $result->{ $column } = $value;
       }
       return $result;
}


you can write:

interface DynamicDBItem {}

function getFromDB(...): DynamicDBItem {
       $result = new class implements DynamicDBItem {};
       foreach ( $this->blah()  as $column => $value ) {
             $result->{ $column } = $value;
       }
       return $result;
}


Regards,

-- 
Rowan Tommins (né Collins)
[IMSoP]