Re^2: getting keys of multi-level hashrefs

When dealing with a large hash (the OP stated this was a small example) it may be better to use each rather than getting the overhead of a temporary list using keys. A skelton example:

while (my ($key,$value) = each %$hashref) {
    print "$key $value\n";
}
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Comment on Re^2: getting keys of multi-level hashrefs Download Code

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Re^3: getting keys of multi-level hashrefs by Neighbour (Friar) on Jul 07, 2010 at 11:24 UTC
Though I doubt the overhead will have a significant impact, even with really large hashes, using each is indeed more optimized. That, and another optimization I thought of after posting my code, would change the subroutine to: `sub DigThroughHashref { my $hr_data = shift; while (my ($key, $value) = each %{$hr_data}) { if (ref ($value) eq "HASH") { print ("Digging through [$key]:\n"); DigThroughHashref($value, @_, $key); } else { print (join ('->', @_) . "->$key - $value\n"); } } ## end while (my ($key, $value) ... } ## end sub DigThroughHashref` [download] All occurrances of $_ are now replaced by $key, and all occurrances of $hr_data->{$_} are now replaced by $value. Also, the seperate variable @keystack is now optimized out. Instead of pushing the to-be-parsed key explicitly onto the end of @keystack, it is now simply added to the arguments of the sub (which results in it being added to @_ inside the sub).	[reply] [d/l]
Re^4: getting keys of multi-level hashrefs by mask_man (Initiate) on Jul 07, 2010 at 20:12 UTC
Thank you so much for responding so quickly the first time. I was able to see your post before your first edit, after experimenting a bit it's safe to say I learned alot from that. Thank you also for taking your time to optimize that sub.	[reply]
Re^5: getting keys of multi-level hashrefs by Neighbour (Friar) on Jul 08, 2010 at 09:50 UTC
Thanks :) Come to think of it, there's another beautification I realised later: Changing `print (join ('->', @_) . "->$key - $value\n");` to `print (join ('->', @_, $key) . " - $value\n");` Because joining first and then appending the last bit of data manually is ugly :-P	[reply] [d/l] [select]