Assign session variable to class variable while initialize the class variable in PHP

Question

Hi,

I have a problem regarding assign session variable to class variable while initialize the class variable.

Check my below code

<?php 
class ModifyProfile
{
    var $userType=$_SESSION['wb_user_type'];

    var $tablename=WB_CUSTOMER_TABLE;
    var $primarykey="nCustomerID";

}
?>

When i run the above code by creating this class object. its giving the parse error for php.

But when i have declare the first variable to blank then its working fine. Please check the code which is working.

<?php 
class ModifyProfile
{
    var $userType='';

    var $tablename=WB_CUSTOMER_TABLE;
    var $primarykey="nCustomerID";
}
?>

so can i assign the session variable to class variable as above or not.

EDIT:

What is the use of public, private and protected keyword while declaring class variable? I am running on php5.

Thanks

Answer 1

do the assignment in constructor.

Answer 2

Try with:

<?php 
class ModifyProfile
{
    var $tablename=WB_CUSTOMER_TABLE;
    var $primarykey="nCustomerID";

    public function __construct() {
        $this->userType = $_SESSION['wb_user_type'];
    }

}
?>

Answer 3

When you assign class variables like that, they actually can't be variable. That is, they have to be a literal value, such as a string, or a constant like in your second example which worked.

Ok:

public $foo = 123;
public $bar = "hello";
public $blah = SOME_CONSTANT;

Not Ok:

public $foo = 123 + 45;
public $bar = "hello"
            . "world";
public $blah = some_function();

What you probably want is instance variables. These are initialised in the class constructor, which is a function which is run whenever you create a new instance of that class.

class Foo {
    public $bar,
           $baths;

    public function __construct($blah) {
        $this->bar = $_SESSION['bar'];
        $this->baths = $blah;
    }
}

Answer 4

Some tipps:

• get rid of var, use private/protected/public instead.
• Assign the needed value in the constructor, see @hsz's answer.
• Don't assume $_SESSION['wb_user_type'] hold's something, it's a bad practice, your class won't be portable.

Good example:

<?php 
class ModifyProfile
{
    protected $tablename=WB_CUSTOMER_TABLE;

    public function __construct($user_type) {
        $this->userType = $user_type;
    }

}

$profile = new ModifyProfile($_SESSION['wb_user_type']);
?>