•list is passed a Directory to
list – we might have put list in class Directory and asked a
Directory to list itself. We didn’t, because Directory knows nothing
about printing. Client sends a getContents message instead, and does its
own printing
•The idiom
test ? yes : no
•loop on contents (like unit test
in hw4)
•line 238: jfile.getSuffix
•Send a message to a JFile object
without knowing whether it’s a TextFile or a Directory