Lab: Experimenting with Accessibility/Visibility


Name:                              Email:                   JAC#:


Part 1. Review





1.2. 
    What output was generated?







1.5. 
    What error was generated?  Why?







1.8. 
    What error was generated?  Why?







1.9. 
    Does the parent class of FormattedDocument have
    a constructor
    with a single String parameter?

    





1.10. 
    Does the FormattedDocument class inherit
    constructors from its parent?

    





1.13. 
    Why did it compile even though there appear to be
    incompatible types?

    





1.15. 
    What output was generated?







1.16. 
    Why were the getDescription() and getText()
    methods in the FormattedDocument class used even though
    doc is declared to be a Document?

    





1.17. 
    The getText() method in the FormattedDocument
    class contains the line temp = super.getText();.  Explain
    this line of code.

    





1.20. 
    What output/error message was generated and why?




Part 2. Accessibility/Visibility Basics





2.2. 
    What error was generated?







2.3. 
    Why was this error generated?

    





2.6. 
    Why was no error generated?

    





2.9. 
    Why was no error generated?

    





2.10. 
    Assuming no other changes, what value will be returned by the 
    firstNonNull() method when it is called.

    





2.11. 
    Why?

    





2.15. 
    What error was generated?







2.16. 
    Why was this error generated?

    





2.18. 
    What changes did you make?

    





2.22. 
    What error was generated?




Part 3. Some Accessibility/Visibility Examples





3.3. 
    Why are no error messages generated?

    





3.5. 
    What error is generated and why?







3.8. 
    Why are no errors generated? 

    





3.9. 
    What's the difference between the public version
    and the protected version?
    Which is better?  Why?

    





3.11. 
    In this case, which version is better?  Why?

    





3.13. 
    What changes can you now make to the
    FormattedDocument class? (Hint: Think about how
    the FormattedDocument class accesses these attributes.)

    





3.14. 
    Do you like these changes?  Why or why not?

    





3.15. 
    Now that the delimiters attribute is protected,
    do you still need the getDelimiters() method?

    





3.16. 
    Should either the getDescription() or 
    getText() methods in the Document
    class  be protected?  Why or why not?