using php objects in strings

[NotionCommotion]

Why does the second string definition cause an error?

<?php
ini_set('display_errors', 1);

$obj=new stdClass();
$obj->p1=123;
$obj->p2=new stdClass();
$obj->p2->p21=123;
$string="foo: $obj->p1";
$string="foo: $obj->p2->p21";

  Quote

Catchable fatal error: Object of class stdClass could not be converted to string in /var/www/html/test2.php on line 9

 

 

[Barand]

Use braces

$string2="foo: {$obj->p2->p21}";

[NotionCommotion]

Thanks Barand, but I knew the solution, but not the "why".  I searched the docs and I couldn't find why it happens or were it is documented.

[Barand]

I suspect it's because it uses "complex string syntax", just as $str = "ABC{$array[1][2]}"; requires the {..} whereas $str = "ABC$array[3]"; does not.

 

http://uk1.php.net/manual/en/language.types.string.php#language.types.string.parsing

[requinix]

Because that's all the "simple" syntax allows: one property. If you're looking for a rationale from the PHP developers as to why only one property indirection is permitted then you're probably going to have to ask them directly.

 

[edit] Ohhh, you mean why is it an error. Not why is it not allowed. Nevermind.

[NotionCommotion]

  On 11/1/2016 at 4:46 PM, requinix said:

Because that's all the "simple" syntax allows: one property. If you're looking for a rationale from the PHP developers as to why only one property indirection is permitted then you're probably going to have to ask them directly.

 

[edit] Ohhh, you mean why is it an error. Not why is it not allowed. Nevermind.

 

Got a phone number?

[Jacques1]

String interpolation in PHP is piss-poor, so either stop using it for anything other than plain variables, or get ready to dive into the parser.

[NotionCommotion]

  On 11/2/2016 at 12:38 AM, Jacques1 said:

String interpolation in PHP is piss-poor, so either stop using it for anything other than plain variables, or get ready to dive into the parser.

 

By diving into the parser, you mean the source code or something else?