what's the diference: "@" and isset function?

[aouriques]

I am using "@" in front of my variables to not report error (undefined).
There are PHP versions that not accept this operator?
I need to know if "@" is better or worst than "isset()".

Thanks.

[AstroTeg]

I personally think suppressing an error is really bad when you have a way (isset()) to work around the error. I'd say use isset().

[swr]

Another vote for isset(). @ doesn't work when you use a custom error handler:

error_reporting(E_ALL);
$x = @$undefined; // No message thanks to @

function error_handler($errno, $errstr, $errfile, $errline) {
    echo "$errstr at $errfile:$errline\n";
}
set_error_handler('error_handler');

$x = @$undefined; // error_handler() is called, even with @