What does @$_GET mean?

Question

I don't understand why someone is using the @ in the code, I have seen it with mysql connections but I don't know what it means.. thanks!

$player_name_orig = @$_GET['player'];
if (!$player_name_orig) {
    die('You must specify a player name');
}

Answer 1

The @ is the error suppression operator.

In this specific context, it's a (wrong!) way to avoid PHP giving a notice if the player key does not exist in $_GET:

If you try this:

unset($_GET['player']); // to make sure
echo $_GET['player'];

You get:

Notice: Undefined index: player in F:\dev\www\index.php on line 35

While if you try this:

unset($_GET['player']); // to make sure
echo @$_GET['player'];

There is no output.

The correct way to do this:

if (empty($_GET['player']) {
    die('You must specify a player name');
}  

Answer 2

The @ will stop any errors from appearing and return false on an error.

So in your code if $_GET['player'] does not exist then the code will go into the if statement

Answer 3

@ Means to ignore errors such as the variable not being set.

Answer 4

the "@" is used to prevent any warning or error message to appear. It's a really bad habit. Doing that a lot of hidden operations are done (removing error handler, and putting it back after).

The right way to do that operation is:

// my_security_filter() is a function that can render FALSE and remove any dangerous thing
$player_name_orig = array_key_exists('player',$_GET)? my_security_filter($_GET['player']) : FALSE;
if (FALSE===$player_name_orig) { ...