Question

I have a question regarding “dynamic” class initialising, let me explain what I mean:

$class = 'User';
$user = new $class();

//...is the same as doing
$user = new User();

So… that’s not the problem, but I am having some trouble doing the same while calling a static variable from a class, for example:

$class = 'User';
print $class::$name;

Which gives out the following error:

Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM in

Off course I have tested doing print User::$name; and that works. So class works.

Why is this and is there a way around it?

Follow up question:
Also is there any valid reasons to not use this “dynamic” way in creating classes?

Answer 1

If you don’t have PHP version of 5.3 and above, and you don’t want to use reflection (which in my opinion is an overkill – unless you want to access multiple static properties) you can define getter function and call it via call_user_func():

class A {
    public static $var = "Hello";
    public static function getVar() {
        return self::$var;
    }
}
$className = "A";
echo call_user_func(array($className, 'getVar'));