Functional Decomposition

Function Global Scoping

• Functions can appear anywhere in the Perl program. They do not need to be declared before they are called.
• By default, all variables in a Perl module are global, that is accessible to both main Perl program and any Perl functions in that module.
• This includes all variables declared with my in the main Perl module.
• Example
  

#!/usr/bin/perl -w
use strict;

my ($GlobalX);

$GlobalX="Hello from Main\n";

print "Before Function, GlobalX = $GlobalX";
aFunction();
print "After Function, GlobalX = $GlobalX";

sub aFunction {
    $GlobalX = "Hello from Function\n";
}

==> Before Function, GlobalX = Hello from Main
==> After Function, GlobalX = Hello from Function