Shopping Cart – Part 7

Goal: Quality control the Store class.

Unchecked exceptions

An unchecked exception crashes the app as a result of badly written code.

You should throw an:

• IllegalArgumentException when the caller passes faulty arguments into a method/constructor.

• IllegalStateException when an object calls its method at a "bad time" (object not in a legal state).

Throwing an unchecked exception forces the caller to improve their code.

Task 1 – Inspecting the Store class

1. The constructor doesn't receive any parameters so there's nothing to check.

2. Should the setItem setter check for a null? No.

   • The code would already throw a NullPointerException. So, throwing an IllegalArgumentException would be redundant.

Upon inspecting the Store class, applying further quality control isn't necessary.