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Question

Hello i just stuck in syntax, can anyone help me with next code?

class User {    
  protected $userID = preg_replace('#[^0-9]#i', '', $_SESSION['user_id']);
  protected $useremail = preg_replace('#[^A-Za-z0-9@_.-]#i', '', $_SESSION['user']);
  protected $userPassword = preg_replace('#[^A-Za-z0-9]#i', '', $_SESSION['user_password']);

  public function CheckUserLogin(){     
    if(!isset($_SESSION['user'])){
      header("location: login.php");
      exit();    
    }

    //Try to find user from session data in database
    $sql = "SELECT * FROM users WHERE id = '$this->userID' AND email = '$this->useremail' AND password = '$this->userPassword' LIMIT 1";
    $res = mysql_query($sql) or die(mysql_error());
    $userMatch = mysql_numrows($res);
    if ($userMatch == 0) {
      header("location: login.php");
      exit();
    }
  }
}

Answer 1

First of all, note that when declaring a property, you cannot assign it a value that's not know at compile-time -- which means you cannot call a function to initialize a property.

This code :

protected $userID = preg_replace('#[^0-9]#i', '', $_SESSION['user_id']);

Is not valid.

As a reference, you can read the Properties page of the manual (quoting the relevant sentence) :

They are defined by using one of the keywords public, protected, or private, followed by a normal variable declaration.

This declaration may include an initialization, but this initialization must be a constant value -- that is, it must be able to be evaluated at compile time and must not depend on run-time information in order to be evaluated.

You should first declare the property ; and, later (in the constructor of your class, for instance), initialize it :

class User {

    protected $userID;

    public function __construc() {
        $this->userID = preg_replace('#[^0-9]#i', '', $_SESSION['user_id']);
    }
}