#!/usr/bin/perl
# Print out a hash by key order, then by value order.

%grades=(kim=>96,al=>63,rocky=>87,chrisy=>96,jane=>9);

# Grades sorted by Student Name:
#        al   63
#    chrisy   96
#      jane    9
#       kim   96
#     rocky   87
print "\nGrades sorted by Student Name:\n";
foreach $key (sort keys %grades) { printf "  %7s   %2d\n",$key,$grades{$key};}

# Grades sorted by Ascending Grades:
#      jane    9
#        al   63
#     rocky   87
#    chrisy   96
#       kim   96
print "\nGrades sorted by Ascending Grades:\n";
foreach $key (sort {$grades{$a} <=> $grades{$b}} keys %grades) {
  printf "  %7s   %2d\n",$key,$grades{$key};
}

# Grades sorted by Descending Grades:
#    chrisy   96
#       kim   96
#     rocky   87
#        al   63
#      jane    9
print "\nGrades sorted by Descending Grades:\n";
foreach $key (sort {$grades{$b} <=> $grades{$a}} keys %grades) {
  printf "  %7s   %2d\n",$key,$grades{$key};
}