Re^2: Printing only the "keys that have a value" in hash

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Re^3: Printing only the "keys that have a value" in hash by aquarium (Curate) on Nov 01, 2010 at 02:17 UTC
just before your main processing instructions `foreach $key(%my_hash) { delete $my_hash{"$key"} if(!exists($my_hash{"$key"})); }` [download] that will get rid of empty keys--assuming you're not interested in these--and henceforth you can now iterate over keys of the hash. the hardest line to type correctly is: stty erase ^H	[reply] [d/l]
Re^4: Printing only the "keys that have a value" in hash by lostjimmy (Chaplain) on Nov 01, 2010 at 02:48 UTC
Unless I'm mistaken, this code won't do anything at all. You're getting each `$key` directly from the hash, so it's always going to exist. Perhaps you meant `if (!defined $my_hash{$key})`? Anyway, checking for defined-ness won't matter either since the "undefined" values are actually empty array refs, which are defined.	[reply] [d/l] [select]
Re^4: Printing only the "keys that have a value" in hash by iphone (Beadle) on Nov 01, 2010 at 02:41 UTC
`#print Dumper( \%Hash_filematches ); -->Shows correct data` [download] But with the below code,the output is shown below `print "PRINTING MATCHED HASHES\n"; foreach my $key ( keys %Hash_filematches ) { delete $Hash_filematches{"$key"} if(!exists($Hash_filematches{"$ke +y"})); my $value = $Hash_filematches{$key}; print "$key => $value\n" ; }` [download] This below is the output.It's still printing the array references as values and also the hash keys without values. `PRINTING MATCHED HASHES array.xml => ARRAY(0x1b26ac8) file.xml => ARRAY(0x1b26af8) data.xml=> ARRAY(0x1b26ae0) multimedia.xml => ARRAY(0x1b26b58 ...... ......` [download]	[reply] [d/l] [select]