Java lab practice demo
Create a class called Invoice that a hardware store might use to represent an invoice for an item sold at the store. An Invoice should include four pieces of information as instance variables—
(a) a part number (type String),
(b) a part description (type String),
(c) a quantity of the item being purchased (type int) and
(d) a price per item (double).
ⓂYour class should have a constructor that initializes the four instance variables.
ⓂProvide a set and a get method for each instance variable. In addition,
Ⓜprovide a method named getInvoiceAmount that calculates the invoice amount (i.e., multiplies the quantity by the price per item), then returns the amount as a double value. If the quantity is not positive, it should be set to 0. If the price per item is not positive, it should be set to 0.0.
✔ Now, write a program named InvoiceTest that demonstrates class Invoice’s capabilities.