How can I verify that a value is present in an array (list) in Perl?

Question

I have a list of possible values:

@a = qw(foo bar baz);

How do I check in a concise way that a value $val is present or absent

Answer 1

Interesting solution, especially for repeated searching:

my %hash;
map { $hash{$_}++ } @a;
print $hash{$val};