Re^3: Hash assignments using map

[japhy]

in reply to Re^2: Hash assignments using map
in thread Hash assignments using map

Right. My point is, why not loop over the elements in @keepers, rather than the keys of the other hash?

my %big_hash = (...);
my @to_keep = ('abc', 'xyz');

%big_hash = map { exists($big_hash{$_}) ? ($_ => $big_hash{$_}) : () }
+ @to_keep;
# or
%big_hash = map { $_ => $big_hash{$_} } grep { exists $big_hash{$_} } 
+@to_keep;