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phperror-handlingoperators

'At' symbol before variable name in PHP: @$_POST

I've seen function calls preceded with an at symbol to switch off warnings. Today I was skimming some code and found this:

$hn = @$_POST['hn'];

What good will it do here?

Solution

  • The @ is the error suppression operator in PHP.

    PHP supports one error control operator: the at sign (@). When prepended to an expression in PHP, any error messages that might be generated by that expression will be ignored.

    See:

    Update:

    In your example, it is used before the variable name to avoid the E_NOTICE error there. If in the $_POST array, the hn key is not set; it will throw an E_NOTICE message, but @ is used there to avoid that E_NOTICE.

    Note that you can also put this line on top of your script to avoid an E_NOTICE error:

    error_reporting(E_ALL ^ E_NOTICE);