in reply to Interchanging hash values

The other solutions are nice, but if you want a more efficient algorithm then it is indeed possible to avoid the sort. An O(N) algorithm is:
#!/usr/bin/perl -w use strict; use Data::Dumper; my %hash = ( Matt => 24, Dana => 19, Eric => 28, Sara => 20, John => 17, Mi +ke => 23, ); if (%hash) { my (@min, @max); while( my ($k,$v) = each %hash ) { @min = ($k,$v) unless @min && ($v > $min[1]); @max = ($k,$v) unless @max && ($v < $max[1]); } $hash{$min[0]} = $max[1]; $hash{$max[0]} = $min[1]; } print Dumper \%hash;
--Dave