READING
CHAPTER 8
SECTION 4
"Types of Exceptions"

- *checked exception*
  - an exception that is checked at compile time
  - method containing must do one of to compile
    - have a throws clause
    - have a try catch block around the statement that throws the exception
- *unchecked exception*
  - aka runtime exception
  - not checked at compile time
  - detected only at runtime
  - e.g.
    - ArithmeticException: division by zero
    - NumberFormatException: trying to convert a string with letters to an int
  - throws clause optional for method containing
    - methods can be implicit propagators
    - because nearly every method can throw a runtime exception
- Error
  - too serious to catch
  - so not required to handle them

Quick Check
1. No, because according to Figure 8.5, IllegalArgumentException is a subclass of RuntimeException, and we know that runtime exceptions needn't be explicitly caught or propagated.
2. Checked exceptions are explicitly checked at compiler time, and thus require that a method that directly or indirectly throws one either include a try-catch block, or include a throws clause in its signature.
3. Yes.  According to Figure 8.5, IOException is not a runtime exception, and this code neither includes a try-catch block, nor includes "throws IOException" in its signature, as is required for checked exceptions.