Week 01 Notes for CS 2500, Section 001 -- Spring 2002

• Take Roll.
• Announcement(s)
  • Week 01 is short: class meets Thursday only.
  • First Lab will be on Tuesday, Feb 19.
  • Progamming I is a prerequisite for programming II, and students without prerequisites may be dropped by the instructor. See me after class if you have not passed the equivalent of CS 1500.
  • The first programming assignment is in place online.
• Pass around a sign-up sheet for new accounts.
• Discuss schedule for first week.
• Pass out course handout(s)
• Go over information in the course description.
• Show class where to get hello world handouts and Jove handouts online:
  • Hello World
  • Jove Help
• Assignment: Students should read the hello world assignment. We will be doing the assignment together in lab on Tuesday.
• Discuss top-down program design methodology using online examples of level-one through level-three programs.
  1. First create a header comment for the program. Use the specs in the assignment to create your description of what the program does.
  2. Invent your algorithm: Conceive of a method for solving the problem. The method must involve just a few steps. Keep the number of steps small by not including much detail at this level. A function must not take up more than about 24 lines of code (a "screenful"). Less is better.
     • The algorithm must be complete: All required tasks of the algorithm are covered by the steps given, even though many details may not be explicitly mentioned.
     • The steps of the algorithm must be in the correct order.
     • Any loop, if-else, or other control structure must be written correctly.
  3. Next translate the algorithm into C++, making it into your main function.
  4. Make "steps" of the algorithm into function calls in the main function. Include parameters in the calls.
  5. Create stubs for the function calls in the main program.
     • Begin each stub by writing a header comment telling what the function will do when completed. (In other words, the header does not tell what the stub function does. It tells what the completed function will do.)
     • Next write code for the stub function. Usually a stub writes a message to let the user know when it is executing. The stub must also return a value if the caller expects one. If the caller expects the function to set the values of other parameters or variables, the stub must do that. Usually the programmer just picks arbitrary values for the stub to return or set.
  6. Compile and test the program. Fix any problems with the main function and stubs.
  7. When everything checks out, start expanding stubs into completed functions. How do you do that? Basically you just do the steps above all over again. Now you are working on a function at the next level down instead of the main function. You must still defer detail. Include only enough detail at each level so that the function has just a few steps.
  8. You work like this over and over, going down level-by-level. Eventually, there will be steps to fill in that are so simple that they can be coded directly into just one or two C++ statements. Once you reach this "bottom level" everywhere in the program, you are finished writing it.