#!C:/perl/bin/perl.exe
use CGI::Carp qw(fatalsToBrowser);
use CGI;
$query = new CGI;

print $query->header;
print $query->start_html(-title=>'Subroutines');

print "<style type='text/css'>	body{ font-size: 90%; font-family: verdana; }</style>";



# -----------------------------------------

print "Results of first subroutine: <BR>";

&printText2("The subroutine will format this text with a large font size.");



# -----------------------------------------

print "<HR><BR> Results of second subroutine: <BR>";

&printText3("The subroutine will format this text with a specified font size.", 1);




# -----------------------------------------

print "<HR><BR> Results of third subroutine: <BR>";


$sum = &sumNumbers1(1,2,3,4,5,6,7,8);
print "The sum of those numbers is $sum. <BR>";




# or, using an array as a parameter:

@numbers = (1,1,1,1,1,1,1);
$sum = &sumNumbers1(@numbers);
print "The sum of those numbers is $sum. <BR>";






print $query->end_html;

# ----------------- Subroutines -----------------------------
# for a good tutorial/overview of Perl subroutines, see
# http://www.comp.leeds.ac.uk/Perl/subroutines.html
#------------------------------------------------------------

# This subroutine accepts parameters
# When the subroutine is called any parameters are passed as a list in the special @_ list array variable.

sub printText2 {
	print "<font size=5> @_ </font><BR>";

} 


# This subroutine accepts more than 1 parameter
# When the subroutine is called any parameters are passed as a list in the special @_ list array variable.
# each parameter can be referenced via $_[0] (first parameter) and $_[1] (second parameter)

sub printText3 {
	
	# 0th parameter is text to be displayed		$_[0]
	# 1st parameter is font size				$_[1]

	print "<font size=$_[1]> $_[0] </font><BR>";

} 

# This subroutine accepts more than 1 parameter
# However, this subroutine does not assume how many variables are being passed to it and uses
# the for loop to parse each parameter

# This example also illustrates how values can be *returned* by a subroutine

# (Note the difference in class between local and global variables.)

sub sumNumbers1 {
	
	$nItems = @_;				# assigns the length of the array to the variable $nItems
	$sum = 0;

	for($i=0;$i<=($nItems-1);++$i){
			$sum = $sum + $_[$i];
	}
    return $sum;

}