sub printString {
    my ($str) = @_;

    print $str;
}

##</code><code>##

printString("Hello world\n");

##</code><code>##

if ($num == 1) {
    sub1();
} elsif ($num == 2) {
    sub2();
} ...

##</code><code>##

use strict;
use warnings;

my $num = 1;
my $mainObj = bless {};
my $handler = $mainObj->can("sub$num");

die "No handler for $num\n" if !defined $handler;
$handler->();


sub sub1 {
    print "Handling case 1\n";
}