For a quick, but possibly wrong solution, you could use a hash slice: 

my %newhash;
@newhash{@array} = @oldhash{@array};

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A pitfall here is that if there's a value in the array that doesn't correspond to a key in the original hash, you'll autovivify an entry.

If you don't have such control over your data, try: 

my %new = map { $_=> $old{$_} } grep { defined $old{$_} } @array;

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The grep gets all the entries in the hash that (a) have a key corresponding to an entry in the array and (b) have defined values. The map turns that list into a hash.

Change that defined to exists if you don't mind getting back keys associated with undefined values.

HTH! 

perl -e 'print "How sweet does a rose smell? "; chomp ($n = <STDIN>); 
+$rose = "smells sweet to degree $n"; *other_name = *rose; print "$oth
+er_name\n"'

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In reply to Re: Mapping array over a hash by arturo
in thread Mapping array over a hash by agoth

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