OOP problem

MagnuM

Hi guys, I'm trying to use the OOP in PHP. I just don't know whats wrong with the following code:

class ContactLoader {

  var $address;
  var $email;

  function ContactLoader() {
    $this->$address = "";
    $this->$email = "";
  }

  function loadContact() {
    $this->$address = "Some address";
    $this->$email = "Some email";
  }

  function getAddress() {
    return $this->$address;
  }

  function getEmail() {
    return $this->$email;
  }  

}

$contactLoader = new ContactLoader();
$contactLoader->loadContact();

print($contactLoader->getAddress());

The last line it printing the "Some email" text, it overwrites the address text somehow.

Any suggestion?

NogDog

First problem I see is that the way you reference your class variables within the class is incorrect: there should only be a "$" before the "this", not before the variable name, e.g. $this->email instead of $this->$email.

MagnuM

Great man, thanks.

It's working ... what a silly man am I.

NogDog

MagnuM;10882586 wrote:
Great man, thanks.

It's working ... what a silly man am I.

I used to do the same thing often enough to be annoying. Fortunately I don't do it nearly as much now (plus using a good IDE that prompts you with known variable names helps).

nrg_alpha

Magnum, I'm just wondering why you have a method to set your $email and $address properties to empty? Would it not be better to introduce those properties as empty, then make your loadContact method accept dual arguments and assign them to your $email and $address properties from there?

class ContactLoader {

 var $address = ""; // sets this property to empty by default
 var $email = ""; // sets this property to empty by default

  function loadContact($someAddress, $someEmail) {
    $this->address = $someAddress; 
    $this->email = $someEmail; 
  } 

  ....

MagnuM

I was just testing the constructor and how the OOP works in PHP. I initialized those variables in the constructor.

It's not for production, it's only for fun 🙂

nrg_alpha

ah yes, contructors.. just be aware of the differences between initialising properties statically vs initialising them within the constructor.. doing so statically means that any child classes that extend off of the parent will automatically inherit those initialised properties.. (where as if you initialise properties within a construct, this does not automatically pass this down to extended (child) classes, unless you call the parent construct from within the child class.

Here is a small but worthwhile thread I started not too long ago. Sheds some good light on the subject:
http://www.phpbuilder.com/board/showthread.php?t=10357763

Cheers,

NRG

MagnuM

Many thanks for the tips and link.