Er... yes. It works exactly how you'd expect it to. Or, at least, how I'd expect it to. What did you try? What happened when you tried it?

sub a_subroutine {
  print "this is a subroutine\n";
}

sub another_subroutine {
  print "this is another subroutine\n";
  a_subroutine();
}

another_subroutine();
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Did you try it out? It just works(tm).

I think you should spend some time in the first chapters of some Perl books for beginners, like Learning Perl by our own merlyn, or Beginning Perl by Simon Cozens. If you look closely at the latter page, you can find a link to a free online version.

use strict;
use warnings;

bongo(\&bingo);

sub bingo {
    print "bingo";
}

sub bongo {
    my $p = $_[0];
    $p->();
}
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use strict;
use warnings;

whatever();

sub whatever {
    my $value = 5;
    $value = increment($value);
    print $value;
}

sub increment {
    return $_[0] + 1;
}
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