Question

In the following example

class Employee
{
    var $name;
    var $city;
    protected $wage;
    function __get($propName)
    {
        echo "__get called!<br />";
        $vars = array("name","city");
        if (in_array($propName, $vars))
        {
            return $this->$propName;
        } else {
            return "No such variable!";
        }
    }
}
$employee = new Employee();
$employee->name = "Mario";
echo $employee->name."<br />";
echo $employee->age;

The output is:

Mario
__get called!
No such variable!

… confuses me, I understand that “__get called!” appears when $employee->name is accesed, but why does it not appear even when $employee->age is accesed? I mean… it’s there but it seems like the __get considers only the return in the if-else statement. How is that possible?

Observation : Of course __get runs when it detects $age does not exist when read, but …when it does run, why doesn’t the echo in it work?

Conclusion: the “__get called!” appeared because of one call of __get, that in which $employee->age is read.

Answer 1

Your assumptions are wrong.

I understand that “__get called!” appears when $employee->name is accesed

No, it doesn’t. __get is only invoked when you attempt to access a member which does not exist. You have defined a publicly accessible member named $name, this is what the line var $name does. Reading/writing to $employee->name will never invoke the magic __get or __set_ methods.

It is not $employee->name that is causing "__get called" to be printed; $employee->name is returning "Mario", the value you assigned to that member, and that is what is being printed. It is $employee->age that is causing "__get called" to be printed.

I’ve tried to better explain the lines and what they do in respect to __get:

$employee = new Employee();
$employee->name = "Mario";      # assign to $name
echo $employee->name."<br />";  # read "Mario" from $name, does NOT invoke  __get
echo $employee->age;            # attempt to read $age, invokes __get

RE: Your observation

Observation : Of course __get runs when it detects $age does not exist when read, but …when it does run, why doesn’t the echo in it work?

The echo does work. The reason you are only seeing one "__get called!" is because __get is only called once, by attempting to access $employee->age.