第六章：散列

1)
use warnings;
my %names = (
 fred => "flintstone",
 barney => "rubble",
 wilma => "flintstone",
);
print "Plz input first name: ";
chomp (my $fName = <STDIN>);
if (exists $names{$fName}){
 print "The last name of $fName is $names{$fName}.\n";
} else {
 print "No $fName exists!\n";
}

2)
use warnings;
print "Enter some string: \n";
chomp (my @array = <STDIN>);
foreach (@array){
 $sum{$_} += 1;
}
foreach (sort keys %sum){  # keys 函数
 print "$_ => $sum{$_}\n";
}