I have a constants I want to return by a function like this:
public function getConst($const)
{
$const = constant("Client::{$const}");
return $const;
}
But this is giving me an error:
constant(): Couldn't find constant Client::QUERY_SELECT
This however, does work:
public function getConst($const)
{
return Client::QUERY_SELECT;
}
Why not?
In fact this works just fine: http://3v4l.org/pkNXs
class Client {
const QUERY_SELECT = 'foo';
}
$const = 'QUERY_SELECT';
echo constant("Client::{$const}"); // foo
The only reason this would fail is if you're in a namespace:
namespace Test;
class Client {
const QUERY_SELECT = 'foo';
}
$const = 'QUERY_SELECT';
echo constant("Client::{$const}"); // cannot find Client::QUERY_SELECT
The reason for that is that string class names cannot be resolved against namespace resolution. You have to use the fully qualified class name:
echo constant("Test\Client::{$const}");
You may use the __NAMESPACE__ magic constant here for simplicity.
__NAMESPACE__ doesn't help if I'm in another namespace than the class with the constant which I want to refer to with an alias (using use).
If you want to use the ReflectionClass, it would work.
$reflection = new ReflectionClass('Client');
var_dump($reflection->hasConstant($const));
More verbose example, it might be over kill ( not tested )
public function getConst($const)
{
$reflection = new ReflectionClass(get_class($this));
if($reflection->hasConstant($const)) {
return (new ReflectionObject($reflection->getName()))->getConstant($const);
}
}
