PHP variables in classes

Question

I have the following code (I'm a Dot Net developers and I thought if I can bring my OOP knowledge to PHP)

class user {
    var $_un;
    function user($un) {
     $_un = $un;
    }
    function adduser() {
    }
    function checkuser() {
    }
    function printuser () {
     echo $_un;
    }
}

$newuser = new user('Omar Abid');
$newuser->printuser();

So the problem is simple "$_un" is empty!! I want it to be filled, when the class is created using the constructor and then saved.

I used to do that in C# .net, but here it doesn't work for some reasons. Thanks!

Answer 1

In order to access class members in PHP you need to use $this-> .

So what you're currently doing is declaring a local variable called $_un, rather than assigned to the member variable $this->_un .

Try changing your code to:

function user($un) {
 $this->_un = $un;
}

function printuser () {
    echo $this->_un;
}

And it should work.

Answer 2

Use this construct.

class user {    
  var $_un;    
  function user($un) 
   {
      $this->_un = $un;    
    }
 }

Answer 3

Use :

function user($un) {
    $this->_un = $un;
}

Answer 4

in php you have to use $this to access variables (or methods) of the current class, this is necessary to distinguish class members from local variables

Answer 5

Rather than user() you should use __construct(), it's the preferred way to add a Constructor in PHP5. Also consider to add visibility to your methods and members (public / protected / private)

public function __construct($un) {
    $this->_un = $un;
}