Using Java in the Intro CS Course Sequence LACS Meeting July 25, 1997

Strengths

• Pure object-oriented
• Simple conceptual model (compared to C++)
• Type safe - mostly static, some dynamic
  • No unchecked casts
• No explicit pointers / garbage collection
• Separation between classes and interfaces (abstraction)
• Support for information hiding (public, protected, etc.)
• Good support for GUI (1.1 better than 1.02)
• Support for exceptions, threads
• Packages provide some support for name-space control
• Fixed some C syntax (booleans)

Weaknesses

• C syntax:
  • Switch statements
  • Wrong order for declarations
• Still too complex
  • conversions (25 pp. of rules)
  • static overloading
• No support for parametric polymorphism (yet!).
  • Requires use of Object type for container types.
  • Requires lots of gratuitous down-casts.

• Widely available on multiple platforms
• Multi-platform executables, work under browsers
  • GUI/graphics display not always same
• Java 1.1 now out - different GUI philosophy from 1.02
• Debuggers slow in coming out - but Metrowerks fine on Mac.
• Compilers and interpreters still pretty slow.

• Teach OO design
  • Objects early
  • Adding components to systems
  • Interface vs class
  • Code reuse/incremental changes
• Focus on interaction
• Concurrency

• Josephus assignment
• Maze demo
• Calculator assignment
• Animal assignment
• Timer assignment

• No good Java books to learn on own in 2 weeks.
• General dearth of Java-based CS1 and CS2 texts.
• Careful selection of examples is key.
  • Don't expect students to get design on own
  • Don't throw too much at them too fast
  • Graphics great, but not same on all platforms/browsers.
• Correct use of layout manager takes patience.
• Java 1.1 GUI use significantly different from 1.02.

• Don't teach like traditional imperative:
  • Go with object-oriented philosophy
  • Teach OO design
  • Use GUI interface and take advantage of interaction and concurrency
• Applets worked well:
  • make fun to show off projects.
  • But limited use of files.
  • Probably do both applets and applications (can package each inside other).
• Lots of info available on-line.

• Java now in CS2, graphics.
• Probably in CS1 second semester.
• Some systems courses might shift to it
• Where will students learn C?
• Will they use any other languages in course work outside of AI or Programming Languages?

If so, shouldn't we be teaching that?