FreeKB (2024)

Perl (Scripting) - Count keys and values in a hash

In Perl, there are 2different kinds of hashes.

• A hash, which is defined by the % and ( ) characters - %hash = ( );
• A reference hash, which is defined with the $ and { } characters - $hash = { };

Empty hash

Let's say you have the following empty hash that contains no keys and no values.

my %hash;

The following can be used to print the number of keys and values in the hash.

my $keys = keys %hash;my $values = values %hash;print "keys = $keys \n";print "values = $values \n";

Which should return the following.

keys = 0values = 0

Hash with keys and values

Let's append some keys and values. In this example, the hash has three keys (employee, id,department) and three values (John Doe, 123456, Engineering)

my %hash;$hash{employee} = "John Doe";$hash{id} = "123456";$hash{department} = "Engineering";

Print the number of keys and values in the hash.

my $keys = keys %hash;my $values = values %hash;print "keys = $keys \n";print "values = $values \n";

Which should return the following.

keys = 3values = 3

Did you find this article helpful?

If so, consider buying me a coffee over at