Re: Using grep to remove array element from HoAoH leaving empty array-hash element

I don't think you're on the right track with the hash element not disappearing idea.

There are three possibilities:

1) $last is not defined. Easily verifiable with die("\$last is undef.\n") unless (defined($last));.

2) The key last is not found in %$_ for some element $_ of @{$bros->{$yr}}, as in the following structure:

$bros = {
   '1976' => [
      {
         'first' => 'Eric',
         # oops! no 'last'!
      },
   }
};
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3) $_->{last} is not defined for some element $_ of @{$bros->{$yr}}, as in the following structure:

$bros = {
   '1976' => [
      {
         'first' => 'Eric',
         'last'  => undef,  # oops! no value for 'last'!
      },
   ],
};
[download]

For (2) and (3), printing out $bros or @{$bros->{$yr}} with the help of Data::Dumper might help you locate the record with the missing 'last' or the one which has undef for value.

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Re^2: Using grep to remove array element from HoAoH leaving empty array-hash element by Popcorn Dave (Abbot) on Aug 11, 2004 at 05:10 UTC
I think you're on to something with 2 and 3. Take a look at my reply and you'll see the Data::Dumper results. I'm getting an empty hash after the grep which appears to be appended to the end of the array. I think that is where grep is throwing the error, but I'm stumped on how to rectify that. Useless trivia: In the 2004 Las Vegas phone book there are approximately 28 pages of ads for massage, but almost 200 for lawyers.	[reply]
Re^3: Using grep to remove array element from HoAoH leaving empty array-hash element by ikegami (Patriarch) on Aug 11, 2004 at 05:23 UTC
It's not the 'after' that's important. The warning is your grep condition telling you the data is wrong (i.e. different than expected) before grep is called. Data::Dumper shows us this bad data: the extra "{}" at the end of the list in the 'before' dump. What you must do now is figure out how that extra (fieldless) record is being added to your 'database'.	[reply]