use strict;
use warnings;
my %hash=("bob" =>123,
          "tom" => "CAT"); #Assign values
change (\%hash);

#Print New Values
print "$_ = $hash{$_}\n" foreach keys %hash;


sub change{
    my $hashRef = shift;   #Get the reference to the values
    foreach (keys %$hashRef){
        print "$_ = $hashRef->{$_}\n";
        $hashRef->{$_} .= "hello"; #Change Values
    }
}

##</code><code>##

tom = CAT
bob = 123
tom = CAThello
bob = 123hello