在我的类中使用全局变量导致意外的语法

Question

I have a class that requires a variable that is defined out of the scope of it. So i tried using global but, this causes this error:

syntax error, unexpected 'global' (T_GLOBAL), expecting function (T_FUNCTION)

I am unsure if I have put it in the wrong place or using the global keyword incorrectly.

My code looks like this:

$data = new testClass();

class System
{
    private $values;
    global $data;

    public function __construct()
    {

    }
    public function test()
    {           
        return $data->get();
    }
}
$system = new System();
echo $system->test();

So i was wondering how do I get the $data variable to be defined in my class? My use of global seems to be incorrect, I also put the global declaration in the __contrust() function but that didn't work either.

Answer 1

Define the global variable within the function instead of the class:

public function test()
{           
    global $data;
    return $data->get();
}

EDIT: Alternate idea:

class System
    {
        private $values;
        private $thedata;

    public function __construct($data)
    {
        $this->thedata = $data;
    }
    public function test()
    {           
        return $this->thedata->get();
    }
}

$data = new testClass();
$system = new System($data);
echo $system->test();