Chapter 17: Making our own Exceptions

Question 1

What are checked an unchecked exceptions

Answer 1

Checked- we must have a catch clause or declare throws. Checked at compile time
Unchecked- The rule is relaxed e.g. run time exceptions and similar

Question 2

Describe the exception hierarchy

Answer 2

Throwable
/ \
Error Exception
/ \
Runtime IO
/
Index out of bounds
/ \
Array index out of bounds | String index out of bounds

Question 3

Why can we make our own exceptions?

Answer 3

Exceptions are in an inheritance hierarchy

Question 4

How do we make our own exceptions?

Answer 4

1. Choose a standard class closest to what we want. Exception if checked, runtime if unchecked.
2. Make a subclass of it
3. Write four constructor methods:
   no method parameters
   one that takes a string
   one with string and throwable
   one with only throwable