PHP Interview questions 20

81) How we load all classes that placed in different directory in one PHP File , means how to do auto load classes

Ans :      by using spl_autoload_register('autoloader::funtion');

Like below

class autoloader

{

public static function moduleautoloader($class)

{

$path = $_SERVER['DOCUMENT_ROOT'] . "/modules/{$class}.php";

if (is_readable($path)) require $path;

}

public static function daoautoloader($class)

{

$path = $_SERVER['DOCUMENT_ROOT'] . "/dataobjects/{$class}.php";

if (is_readable($path)) require $path;

}

public static function includesautoloader($class)

{

$path = $_SERVER['DOCUMENT_ROOT'] . "/includes/{$class}.php";

if (is_readable($path)) require $path;

}

}

spl_autoload_register('autoloader::includesautoloader');

spl_autoload_register('autoloader::daoautoloader');

spl_autoload_register('autoloader::moduleautoloader');

82) How many types of Inheritances used in PHP and how we achieve it

Ans :      As far PHP concern it only support single Inheritance in scripting.

we can also use interface to achieve multiple inheritance.

                 

83)          PHP how to know user has read the email?

Ans :      Using Disposition-Notification-To: in mailheader we can get read receipt.

Add the possibility to define a read receipt when sending an email.

It’s quite straightforward, just edit email.php, and add this at vars definitions:

var $readReceipt = null;

And then, at ‘createHeader’ function add:

if (!empty($this->readReceipt)) {

$this->__header .= ‘Disposition-Notification-To: ‘ . $this->__formatAddress($this->readReceipt) . $this->_newLine;

}

84) What are default session time and path?

Ans :      default session time in PHP is 1440 seconds or 24 minutes

Default session save path id temporary folder /tmp

85) how to track user logged out or not? when user is idle ?

Ans : 85                By checking the session variable exist or not while loading th page. As the session will exist longer as till browser closes. The default behaviour for sessions is to keep a session open indefinitely and only to expire a session when the browser is closed. This behaviour can be changed in the php.ini file by altering the line session.cookie_lifetime = 0 to a value in seconds. If you wanted the session to finish in 5 minutes you would set this to session.cookie_lifetime = 300 and restart your httpd server.