perl function ref

The ref function in Perl is used to return a string containing the type of the referenced object.

Here's an example:

my $scalar = "Hello, world!";
my @array = (1, 2, 3);
my %hash = ('key1' => 'value1', 'key2' => 'value2');
my $ref_scalar = \$scalar;
my $ref_array = \@array;
my $ref_hash = \%hash;

print ref($ref_scalar), "\n"; # prints "SCALAR"
print ref($ref_array), "\n"; # prints "ARRAY"
print ref($ref_hash), "\n"; # prints "HASH"

In this example, the ref function is used to determine the type of the referenced object. The ref_scalar variable is a reference to a scalar, so ref($ref_scalar) returns "SCALAR". The ref_array variable is a reference to an array, so ref($ref_array) returns "ARRAY". The ref_hash variable is a reference to a hash, so ref($ref_hash) returns "HASH".