when is the __construct function really called?

Question

I saw a code like this in starttutorial.com:

class Database
{
    private static $dbName = 'crud_tutorial' ;
    private static $dbHost = 'localhost' ;
    private static $dbUsername = 'root';
    private static $dbUserPassword = 'root';

    private static $cont  = null;

    public function __construct() {
        die('Init function is not allowed');
    }
}
public static function connect()
{
   // One connection through whole application
   if ( null == self::$cont )
   {     
    try
    {
      self::$cont =  new PDO( "mysql:host=".self::$dbHost.";"."dbname=".self::$dbName, self::$dbUsername, self::$dbUserPassword);  
    }
    catch(PDOException $e)
    {
      die($e->getMessage()); 
    }
   }
   return self::$cont;
}

and somewhere in the middle of the php file that included this class. I saw this line of code.

$pdo = Database::connect();

From what i know, the __construct method is called when an instance of this class is instantiated. My question is, will the code above call the magic method?

Not if no new object instance is created inside the `connect()` method - essentially they're creating a static class : http://stackoverflow.com/questions/468642/is-it-possible-to-create-static-classes-in-php-like-in-c (presumably the class example here is a snippet) — CD001, Mar 14 '16 at 10:24
Have you tried the code?? I believe it will work but the best way is to try it :o) But in answer to your indirect question - the constructor won't be called. — Ukuser32, Mar 14 '16 at 10:34

score 1 · Answer 1 · answered Mar 14 '16 at 10:36

will the code above call the magic method?

No because __construct will only be called during class instantiation like below.

$db = new Database();

The time you instantiate a class is the time __construct() is called.

by declaring your methods as static is the time you can use that static method without instantiating your Database class like

Database::connect()

when is the __construct function really called?

1 Answers1