sub myMethod {

    my ($param) = @_;
    
    return sub {
    
        if ($param) {
            print "Woohoo, you have successfully passed in a parameter ($param).\n";
        } 
        else {
            print "You have not attempted to pass in a parameter.\n";
        }
    }
    
}

my $methodWithoutParam = myMethod();
$methodWithoutParam->();

my $methodWithParam = myMethod('My Param');
$methodWithParam->();