Re: can i rename hashref keys?

Actually hash keys are read only (that's the point: you can only successfully build a hash table if the hash function always returns the same value).

But you can delete pairs, and add them with a different key:

my %name_changes = (
   mm   => 'month',
   yyyy => 'year',
);
for (keys %name_change){
    $h->{$name_change{$_}} = $h->{$_};
    delete $h->{$_};
}
[download]

You have to decide for yourself if that's worth the effort, or if you just want to rebuild the hash anew.

Comment on Re: can i rename hashref keys? Download Code

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Re^2: can i rename hashref keys? by dave_the_m (Monsignor) on Nov 29, 2007 at 17:09 UTC
Given that delete returns the deleted value, this can be simplified: `my %map = (....); $h->{$map{$_}} = delete $h->{$_} for keys %map;` [download] Dave.	[reply] [d/l]
Re^3: can i rename hashref keys? by lodin (Hermit) on Nov 29, 2007 at 17:24 UTC
Given that `delete` can delete a slice, this can be simplified: `my %map = (...); @$h{values %map} = delete @$h{keys %map};` [download] Update: note that this doesn't break on `%map = (foo => 'bar', bar => 'foo')` that the solutions above may do. lodin	[reply] [d/l] [select]
Re^4: can i rename hashref keys? (...simplified) by tye (Sage) on Nov 29, 2007 at 17:42 UTC
Given that initializing the hash just requires you list a bunch of keys and values, this can be simplified: `@{$h}{qw/ month year day first_name /}= delete # New keys @{$h}{qw/ mm yyyy dd name /}; # Old keys` [download] Yeah, I added some extra braces. - tye	[reply] [d/l]
Re^3: can i rename hashref keys? by Anonymous Monk on Nov 29, 2007 at 17:36 UTC
and even more concisely, using a hash slice: @{$h}{qw{month year day first_name}} = delete @{$h}{qw{mm yyyy dd name +}}; C:\@Work\Perl>perl -wMstrict -e "my $h = { mm => 'July', yyyy => '1975', dd => '31', name => 'Milo', l +ast_name => 'Manara',}; print qq(o/p: \n); print qq($_ => $h->{$_} \n) for keys %$h; @{$h}{qw{month year day first_name}} = delete @{$h}{qw{mm yyyy dd name +}}; print qq(-----\n); print qq($_ => $h->{$_} \n) for keys %$h" o/p: mm => July name => Milo dd => 31 last_name => Manara yyyy => 1975 ----- month => July day => 31 first_name => Milo year => 1975 last_name => Manara [download]	[reply] [d/l]