Exceptions

Exceptions, the way a Java method reports that it cannot finish and hands the problem to whichever caller can deal with it. The expensive part is not the syntax but the temptation: a catch block that makes the red text stop is the cheapest possible fix and the most expensive possible outcome. It covers try, catch and finally, catching a specific type, checked and unchecked exceptions, catching against declaring against wrapping, how an exception travels, three mistakes, and try-with-resources. It leaves out designing an exception hierarchy for a library.