CSC151 2007S, Class 07: Characters and Strings

Admin:
* Any announcements of events your colleagues should attend?
* Any questions on HW4?
* Reading for Friday: Procedures.
* Email fixes on Friday.

Overview:
* Additional lessons from yesterday.
* Short introduction to strings.
* Lab.

/On Numeric Procedures/

* What is a parameter (argument, operand)
  * When you write (OPERATOR EXP EXP EXP)
    it's the name we use for the expressions
* remainder
  * How many parameters (argument, operand)?
    * Two
  * What types?
    * Integers, the second of which is NOT 0
  * Computes what's left over after you divide the first expresssion
    by the second
  * What if a parameter is negative?
    (remainder 10 -3)
	(remainder -10 3)
	(remainder -10 -3)
    * The sign of the remainder is the same as the sign of the
      dividend.
* modulo
  * Sam claims (with no supporting evidence) that it's similar to
    remainder
    * How?  Ttat sign thing
    * Gives "the same answer", at least when both numerator and divisor 
      are positive.
  * How does it differ from remainder?
* max
  * How many parameters?
  * What types?
* lcm
  * How many parameters?
  * What types?

/Additional learning outcomes (or so Sam hopes)/
* You need to think carefully about what a procedure does.
* Esp. important when you define your own.
* But hey, even your TA screws up.
* But try, anyway ("Hey, what happens if I use a negative nubmer/0/something else weird")

/Where to put answers/
* Defniitions pane
  * Can be saved.
* Interactions pane
* Students hate the definitions pane
  + Takes longer
  + No "Escape-P"
  + Gets cluttered.

/Notes on Characters and Strings/
* None!

/Lab!/

* Why do we worry about collating sequences?
  * To avoid ambiguity!