In PHP, what is the significance of '@' as a prefix to the variable?

In PHP
Whats the difference between
$yourname = @$_POST['yourname']; AND
$yourname = $_POST['yourname'];

In particular, what is the significance of '@' as a prefix to the variable?

Thanks in advance

Anonymous wrote:

> In PHP
> Whats the difference between
> $yourname = @$_POST['yourname']; AND
> $yourname = $_POST['yourname'];
>
> In particular, what is the significance of '@' as a prefix to the
> variable?

It suppresses any warning messages.

For example if you did this:

error_reporting(15);
print $foo;

you'd get an error along the lines of "Notice: Undefined variable: foo
in /home/chris/websites/toolboxa/test/run.php(48)" because the error
reporting level is set to show warnings in this example.

If you did

error_reporting(15);
print @$foo;

you won't get an error message / warning.

I hadn't seen it used for prefixing variables before but it is commonly used
when calling functions to suppress the error messages they disply eg:

$fp = @fopen('foo.txt', 'r');
if($fp) {
/* the file is open so do something here */
}
else {
/* the file couldn't be opened so do something else here */
}

Without the @ you'd end up with an error along the lines of "Warning:
fopen(foo.txt): failed to open stream: No such file or directory
in /home/chris/websites/toolboxa/test/run.php(48)" which you may not want
output to your webpage, console etc when you can deal with it in code.

--
Chris Hope - The Electric Toolbox - http://www.electrictoolbox.com/

.oO(Chris Hope)

>If you did
>
> error_reporting(15);
> print @$foo;
>
>you won't get an error message / warning.

@ should only be used for functions if you handle errors yourself. Using
it to avoid notices about undefined variables/offsets is bad code. (IMHO
as bad as turning off notices completely on a development system.)

Micha

Michael Fesser wrote:

> .oO(Chris Hope)
>
>>If you did
>>
>> error_reporting(15);
>> print @$foo;
>>
>>you won't get an error message / warning.
>
> @ should only be used for functions if you handle errors yourself. Using
> it to avoid notices about undefined variables/offsets is bad code. (IMHO
> as bad as turning off notices completely on a development system.)

I completely agree with you. I think coding in development with notices ON
is essential. It helps you catch bugs more easily if they're related to a
variable not already being set when you first reference it.

--
Chris Hope - The Electric Toolbox - http://www.electrictoolbox.com/