Today, we’ll look at a simple example: a subroutine that calculates the final price of merchandise with a price, discount, and tax rate given by the user. The subroutine itself resides at the bottom of the program, but is called earlier.<\/p>\n #!\/usr\/bin\/perl Note the subroutine definition starts with sub<\/span>. A subroutine defined as sub bob1<\/span> would be invoked with the call &bob1(parameter list)<\/span>.<\/p>\n For Christmas Day, this is probably enough. I will be discussing the issue of parameters in a coming post.<\/p>\n To all my readers: Happy Holidays. As with every post, I hope this one finds you in good spirits:)<\/p>\n Source:<\/em><\/p>\n McGrath, Mark. Perl in easy steps.<\/em> Southam: Computer Step, 2004.<\/p>\n
\nBack in my November 14 post<\/a> I opened up the discussion on subroutines. In computer science, a subroutine is a self-contained body of code that performs a specific task.<\/p>\n
\nprint “Hello. Welcome to the final price calculator.\\n”;
\nprint “Enter the sticker price of the merchandise, please.”;
\n$price=<STDIN>;
\nprint “Enter the discount percentage, if there is one.\\n”;
\nprint “For example, 25 means 25 percent off.”;
\n$discount=<STDIN>;
\nif(!$discount){
\n$discount=0;
\n}
\nprint “Now, enter the tax percentage; eg., 12 means 12 percent.”;
\n$taxrate=<STDIN>;
\n&finalprice($price,$discount,$taxrate);
\nsub finalprice{
\n$finprice=$_[0]*(1-$_[1]\/100)*(1+$_[2]\/100);
\nprint “Sticker price is $_[0]”;
\nprint “Discount is $_[1]”;
\nprint “Tax rate is $_[2]\\n”;
\nprint “The final price at the till should be $finprice\\n\\n”;
\n}<\/span><\/p>\n