My confusion was that the goal of these exercises was to "Be the compiler".
The thing is, the
compiler does not have a problem with the coding errors in these exercises. I verified this by typing the
Java programming language statements from the exercises into files called "BooksTestDrive.java" and "Hobbits.java". I then ran these two new files through the Java compiler, and it turns out that they
compile (into *.class files) without any errors. The errors happen
later, when you try to actually
run the resulting classes (via the Java Virtual Machine). Hence the "Be the JVM" "Be the JDK" suggestions. I like the examples and their presentation, and I do hope I am not confusing matters, but I found it confusing that these programs
do compile but
do not run.