# File:	sub5.pl	
# Title: 	Use subroutine	double()	with parameters
#		Asks for a number returns double. Do this until you want to.
# Author:	Mihaela Malita  
#	 	Input a number? 5		
#		Double is 10
#		Continue(y/n)? n
#		Bye
$yesorno = 'y';
while($yesorno eq 'y') {
	print "Input a number? ";
	$n = <STDIN>;				# read  $n
	print "Double is " ,double($n);     # invokes subroutine double($n) 
	print "\nContinue(y/n)? ";
	$yesorno = <STDIN>;	
	chop($yesorno);	
}
print "Bye";
exit;
########## arguments are in an array called @_
sub double {
	my($x) = @_;				# $x is a local PARAMETER takes value of $n
	return $x * 2;				# result is computed and returned 
}