http://www.perlmonks.org?node_id=650964

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi guys, hope you can help on this one. I have a hash which is filled from lines in a file, after a split of the line a hash is filled defined as  $time{$recordNumber}. Later on in the script I want to check if  $time{$recordNumber} exists, and if not enter the if statement. I tried using
if ($time{$recordNumber} == undef) #147 { $time{$recordNumber} = 10000; }
but got  Use of uninitialized value at ././monitor-dataset-age line 147 It's not no, because it's not there...but I'm testing to see if it's not there!? Any help much appreciated, Many thanks, Kim