将URL参数传递给类

Question

How do I pass a URL parameter to a class in PHP?

$questionID = isset($_GET['question']) ? ($_GET['question']) : 0;

class Question {    
    public function __construct() {
        $this->id = $questionID;
    }

It's saying $questionID is undefined in the constructor.

Answer 1

$_GET is globally accessible, but $questinID isn't.

What you can do is either access $_GET from within the class.

class Question {    
    public function __construct() {
        $this->id = isset($_GET['question']) ? $_GET['question'] : 0;
    }
 }

Or pass it to the constructor.

$questionID = isset($_GET['question']) ? ($_GET['question']) : 0;
class Question {    
    public function __construct($questionID) {
        $this->id = $questionID;
    }
}
$question = new Question($questionID);

The second one is the preferred method, since it allows you to create questions in a more flexible way which, for instance, makes it easier to create unit tests.