in reply to Subroutines vs Modules

After reading all of these helpful replies, I decided to try out a subroutine and attempt to better understand the syntax by adding comment: 
#! /usr/bin/perl -w

sub of_all_things {
 print "You called me!\n"; #will print this when called
  $one*$two;   #Here are the workings that will return value
}


$one = 12;
$two = 10;
$three=&of_all_things; #return value
$four=2*$three; #using the return value
  print "2 x 120 = $four\n";

[download]

OUTPUT: 
You called me!
2 x 120 = 240

[download]

This seems to work out on my box, but I am most concerned as to whether my comments are aiming at in the right direction?


Es gibt mehr im Leben als Bücher, weißt du. Aber nicht viel mehr. - (Die Smiths)"

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Re^2: Subroutines vs Modules
by Argel (Prior) on Dec 30, 2005 at 21:22 UTC
    That works but better practice (i.e. coding style, etc.) would be: 
    #! /usr/bin/perl
use strict;
use warnings;

#////////////////////////////////////////
sub whoami {
    print "Just entered subroutine ", (caller(1))[3], "\n";
    return;
}

#////////////////////////////////////////
sub one_times_two {
    whoami();
    my( $one, $two ) = @_;
    return $one * $two;
}

#////////////////////////////////////////

my $one   = 12;
my $two   = 10;
my $three = one_times_two( $one, $two );
my $four  = 2 * $three;

print "2 x $three = $four\n";

exit 0;

    [download]
    With output: 
    Just entered subroutine main::one_times_two
2 x 120 = 240

    [download]
    Note: I beleive you need Perl 5.6 or greater for "use warnings".

    -- Argel

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