Æliens

1. What are the basic characteristics of object-oriented languages?
2. How would you classify object-oriented languages? Name a few representatives of each category.
3. What do you consider to be the major characteristic of the object model supported by C++? Explain.
4. Why would you need friends?
5. How would you characterize the difference between object-based and object-oriented?
6. Along what orthogonal dimensions would you design an object-oriented language? Explain.
7. Give a characterisation of active objects. In what situations may active objects be advantageous?
8. How would you characterize prototype-based languages?
9. What are the differences between inheritance and delegation? Does C++ support delegation? Explain. And Java?
10. How would you characterize the concept of a class?
11. Can you sketch the meta architecture of Smalltalk?
12. How would you phrase the postulates underlying class-based languages? Can you give a reflective version of these postulates?

A concise treatment of programming languages is given in  [BG94]. For a collection of papers on object-oriented concepts, see  [KL89]. Further, you may want to consult  [Wegner87], which contains the original presentation of the discussion concerning the distinction between {\em object-based} and {\em object-oriented}. Concurrency is studied in  [AWY93]. For Java, read the original white paper,  [Java]. An interesting extension of C++ is described in  [Petitpierre98]. At the corresponding web site, ltiwww.epfl.ch/sCxx , there is much additional material. Finally, for an account of the design and evolution of C++, read  [Stroustrup97]. For more information on C++, visit www.accu.org , and for Java, www.javasoft.com .