what does this code mean?

unknowngiver · 12-30-2006, 08:37 PM

Hey
i m reading a tutorial and they dont really explain what this line means:

PHP Code:

  $username = (@$_SESSION['username']) ? @$_SESSION['username'] : @$_COOKIE['username'];

Noobie · 12-30-2006, 11:19 PM

DUnno why they use the @ but it means

PHP Code:

  if($_SESSION['username']){

????: NamePros.com http://www.namepros.com/programming/275047-what-does-this-code-mean.html
 $username = $_SESSION['username'];

}else{

$username = $_COOKIE['username'];

}

I guess if the session variable 'username' isn't empty, assign it to variable username, else assign the cookie 'username' to the variable 'username'

Peter · 12-31-2006, 06:53 AM

They have put the @ there I believe in case the session is not initialized. If it is not you would get a warning (an @ sign suppresses warnings).

Matthew. · 12-31-2006, 07:21 AM

To add to what has been said, the line is what is called a ternary operator. I wrote a tutorial about them here:

http://www.zoomcities.com/forum/showthread.php?tid=2362

I do not know why they have used the @ sign to suppress a potential warning either as there will not be one. That line i actually better written as:

PHP Code:

  $username = (strlen($_SESSION['username']) > 0) ? $_SESSION['username'] : $_COOKIE['username']; 

????: NamePros.com http://www.namepros.com/showthread.php?t=275047

Peter · 12-31-2006, 10:33 AM

Originally Posted by Matthew.

I do not know why they have used the @ sign to suppress a potential warning either as there will not be one. That line i actually better written as:

Actually that depends on what error level you have php set as. If you have it set as E_ALL then the following errors will be encountered:-

Quote:

Notice: Undefined variable: _SESSION in PHPDocument1 on line 3
????: NamePros.com http://www.namepros.com/showthread.php?t=275047

Notice: Undefined index: username in PHPDocument1 on line 3

The reason you do not get errors will be because you have it set to a lower level .

Matthew. · 12-31-2006, 10:48 AM

True, i tend to advise most people to ignore notices unless they want to spend 90% of their time on endless pursuits of perfection.

PHP Code:

  error_reporting(E_ALL ^ E_NOTICE); 

????: NamePros.com http://www.namepros.com/showthread.php?t=275047

FTW lol.

Peter · 12-31-2006, 11:39 AM

Originally Posted by Matthew.

True, i tend to advise most people to ignore notices unless they want to spend 90% of their time on endless pursuits of perfection.
????: NamePros.com http://www.namepros.com/showthread.php?t=275047

PHP Code:

  error_reporting(E_ALL ^ E_NOTICE);

FTW lol.

I agree that you should use E_ALL ^ E_NOTICE on a production server but I always prefer to run E_ALL when testing. Any script you write SHOULD be able to be run without the need to suppress the notices.

jerometan · 01-01-2007, 03:05 AM

Originally Posted by filth@flexiwebhost

Originally Posted by Matthew.

True, i tend to advise most people to ignore notices unless they want to spend 90% of their time on endless pursuits of perfection.

PHP Code:

  error_reporting(E_ALL ^ E_NOTICE);

FTW lol.

I agree that you should use E_ALL ^ E_NOTICE on a production server but I always prefer to run E_ALL when testing. Any script you write SHOULD be able to be run without the need to suppress the notices.

It is sometimes tedious to remove all notices, especially when using libraries.
????: NamePros.com http://www.namepros.com/showthread.php?t=275047
A suggestion would be to use php.ini or htaccess to change display_errors to off.
Errors may reveal information to aid a hacking attempt.

beaver6813 · 01-01-2007, 03:14 AM

Showing all notices can be very annoying, for example if i did:

PHP Code:

  if($_GET[code'] == 21) { 

????: NamePros.com http://www.namepros.com/showthread.php?t=275047

And code wasn't active, it would mean that i would have to put in more code above that to check, and to be honest in my opinion its just a waste of time and space.

Matthew. · 01-01-2007, 05:41 AM

Originally Posted by beaver6813

Showing all notices can be very annoying, for example if i did:

PHP Code:

  if($_GET[code'] == 21) {

And code wasn't active, it would mean that i would have to put in more code above that to check, and to be honest in my opinion its just a waste of time and space.

If you did that you would get one whopping parser error lol

Peter · 01-01-2007, 05:59 AM

Originally Posted by beaver6813

Showing all notices can be very annoying, for example if i did:

PHP Code:

  if($_GET[code'] == 21) { 

????: NamePros.com http://www.namepros.com/showthread.php?t=275047

And code wasn't active, it would mean that i would have to put in more code above that to check, and to be honest in my opinion its just a waste of time and space.

all it would take to fix that notice is using the isset function on $_GET['code'] so the code would end up:-

PHP Code:

  if(isset($_GET['code']) && $_GET['code'] == 21) {

(also helps to put the right amount of quotes in)

beaver6813 · 01-01-2007, 07:45 AM

Originally Posted by filth@flexiwebhost

all it would take to fix that notice is using the isset function on $_GET['code'] so the code would end up:-

PHP Code:

  if(isset($_GET['code']) && $_GET['code'] == 21) { 

????: NamePros.com http://www.namepros.com/showthread.php?t=275047

(also helps to put the right amount of quotes in)

Gimme a break

12-30-2006, 08:37 PM	THREAD STARTER #1 (permalink)
unknowngiver Senior Member Join Date: May 2005 Location: Ontario Canada Posts: 3,088	what does this code mean? Hey i m reading a tutorial and they dont really explain what this line means: PHP Code: `$username = (@$_SESSION['username']) ? @$_SESSION['username'] : @$_COOKIE['username'];` __________________ Simplifying Engineering \|\| $$ Currency Converter $$ Julsh - Community/Dating Website \|\| Free Image hosting Fresh Proxies \|\| Random Proxy \|\| Troll Board

12-30-2006, 11:19 PM	#2 (permalink)
Noobie NamePros Regular Join Date: Feb 2006 Location: Montreal, Quebec, Canada Posts: 324	DUnno why they use the @ but it means PHP Code: `if($_SESSION['username']){ ????: NamePros.com http://www.namepros.com/programming/275047-what-does-this-code-mean.html $username = $_SESSION['username']; }else{ $username = $_COOKIE['username']; }` I guess if the session variable 'username' isn't empty, assign it to variable username, else assign the cookie 'username' to the variable 'username' __________________ Goldkey.com is a scam What's your BMI? \| Timestamp Generator

12-31-2006, 07:21 AM	#4 (permalink)
Matthew. Senior Member Join Date: Dec 2006 Location: England Posts: 1,568	To add to what has been said, the line is what is called a ternary operator. I wrote a tutorial about them here: http://www.zoomcities.com/forum/showthread.php?tid=2362 I do not know why they have used the @ sign to suppress a potential warning either as there will not be one. That line i actually better written as: PHP Code: `$username = (strlen($_SESSION['username']) > 0) ? $_SESSION['username'] : $_COOKIE['username']; ????: NamePros.com http://www.namepros.com/showthread.php?t=275047`

12-31-2006, 10:48 AM	#6 (permalink)
Matthew. Senior Member Join Date: Dec 2006 Location: England Posts: 1,568	True, i tend to advise most people to ignore notices unless they want to spend 90% of their time on endless pursuits of perfection. PHP Code: `error_reporting(E_ALL ^ E_NOTICE); ????: NamePros.com http://www.namepros.com/showthread.php?t=275047` FTW lol.

01-01-2007, 03:14 AM	#9 (permalink)
beaver6813 NamePros Regular Join Date: May 2005 Location: England Posts: 392 Follow @beaver6813	Showing all notices can be very annoying, for example if i did: PHP Code: `if($_GET[code'] == 21) { ????: NamePros.com http://www.namepros.com/showthread.php?t=275047` And code wasn't active, it would mean that i would have to put in more code above that to check, and to be honest in my opinion its just a waste of time and space. __________________ -Beaver6813.com - Web Developer Extraordinaire!

12-31-2006, 06:53 AM	#3 (permalink)
Peter NamePros Expert Join Date: Nov 2003 Location: Scotland Posts: 5,069	They have put the @ there I believe in case the session is not initialized. If it is not you would get a warning (an @ sign suppresses warnings).

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