9. Ruby Beyond the Basics I

Activity 9.01: Invoice Generator

Solution

1. Create a new Ruby file.
2. Define the invoice_generator method and the p1 and p2 variables to be used in the program using &block and block_given?. We call the invoice_generator method and pass the product prices along with a block of code:

   def invoice_generator(p1,p2, &block)
       yield calc_discount(p1,p2) if block_given?
   end

   The invoice_generator method has a yield keyword, which will only execute the block of code and pass the product prices if the first block of code is passed.

   First, calc_discount is called and then a block code is executed, which, in turn, passes the customer details to the details method.

3. Next, we will define the discount calculator method, calc_discount, which will calculate the discount on the products, add it to the product, and print the final price of the product. calc_discount is the method where we calculate the sum of the product prices and...