I am passing my .cgi perl program a value called loc via GET, to indicate which files it should patch together and display. I want to cover the instance where no name=value is give - say someone just loads up "myperl.cgi" without the "?loc=value".

Can someone tell me what $locvar = $query->param('loc') will produce if no actually loc is passed? I've read that it will return undef but I cant figure out how to check for that, and I've also read that it will return a null '' but I haven't gotten that to work either.

In reply to check for undefined param name by cameltrader

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