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!

Benjamin Cremer · Accepted Answer · 2009-08-18 10:08:34Z

10

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;
}

answered Aug 18, 2009 at 10:08

Benjamin Cremer

4,8221 gold badge26 silver badges30 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

AlxVallejo Over a year ago

If you have 20 variables for example, would you have to list them as arguments in the __construct(var1, var2, etc) ?

John Carter · Accepted Answer · 2009-08-18 10:47:29Z

7

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.

edited Aug 18, 2009 at 10:47

answered Aug 18, 2009 at 10:00

John Carter

55.7k28 gold badges116 silver badges144 bronze badges

1 Comment

Omar Abid Over a year ago

the other function should changes also function printuser () { echo $this->_un; } Thanks it's working correctly now

knittl · Accepted Answer · 2009-08-18 10:07:08Z

3

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

answered Aug 18, 2009 at 10:07

knittl

269k59 gold badges339 silver badges405 bronze badges

Comments

KV Prajapati · Accepted Answer · 2009-08-18 10:00:48Z

2

Use this construct.

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

answered Aug 18, 2009 at 10:00

KV Prajapati

94.8k20 gold badges151 silver badges188 bronze badges

Collectives™ on Stack Overflow

PHP variables in classes

4 Answers 4

1 Comment

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related