We're going to create an Object Oriented Cash Register that can:
This is a test-driven lab! You will need to read the spec file and the test output very carefully to solve this one.
Note that a discount is calculated as a percentage off of the total cash register price (e.g. a discount of 20 means the customer receives 20% off of their total price).
Hint #1: Keep in mind that to call an instance method inside another instance method, we use the
self keyword to refer to the instance on which we are operating. For example:
class Person attr_accessor :age def initialize(age = 0) @age = age end def birthday self.age += 1 end end
Follow along with the specs in
spec/cash_register_spec.rb. Reading along with what the tests are looking for can be really helpful!
Take it one step at a time!
Hint #2: The
apply_discount requires some knowledge about working with an Integer versus a Float in Ruby. Note that
100.class returns Integer while
100.0.class returns Float. Ruby provides methods for changing an object of type Integer to a Float and vice versa.
Hint #3: The
void_last_transaction method will remove the last transaction from the total. You'll need to make an additional attribute accessor and keep track of that last transaction amount somehow. In what method of the class are you working with an individual item?
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