Lecture 11 – October 3^rd

You do NOT need to have a function in the Pascal program due tonight.

I had four (4) procedures but no functions in mine.

3:30 pm section – Here are the things to try that the 2:00pm section started in class. Note that this is more detailed than what I wrote in

The 2:00pm class and that some variable names have been changed. You

Do not need to turn this in but IF YOU DON”T DO IT, YOU WILL HAVE

TROUBLE COMPLETING THE IN-CLASS EXERCISE TO BE DONE ON

THURSDAY.

program StringPlay (input, output);

type myString = packed array [1..35] of char;

var someString : myString;

begin

(* task #1 *)

(* write a little program that will read 5 strings of type myString *)

(* from the keyboard and echo them back. You do not know how long the *)

(* strings are (but they should be less than or equal to 35 characters

(* long). WHAT HAPPENS IF THEY ARE LONGER???? *)

(* task #2 *)

(* try to access - retrieve and/or alter individual characters in *)

(* a string of type myString after getting it and printing it as an *)

(* entity. Print it again after altering it or print a specific *)

(*single character from it before reading the next string *)

(* task #3 *)

(* read a string a of type myString a character at a time. Stop *)

(* when you encounter a blank because you've found a word and *)

(* put it in an array of words . For this task, the following *)

(* type declaration may be useful: words = array [1..10] of myString; *)

end.

Here’s the program we ran in class illustrating the passing of an array into a procedure.

Here is a modified version of the program we ran in class. This program will compile and run because it doesn’t exceed the bounds of the array. However, if you try to store a value in the 6^th position of the 5 element array OR try to print the 6^th element of the 5 element array, the program MAY simply write over one of the other variables OR it MAY crash with a runtime error. The behavior is unpredictable. You should modify the code and test it by running it several times. HOWEVER: it is ALWAYS erroneous to exceed array bounds and you should not do it in your code EVER!!!

Here are some additional notes from last Thursday (September 28^th)

Please read the text and review the Chapter 5 slides again. If you have ANY questions about the material, send me an e-mail with your question and the page that raised the question by Monday, October 9^th. Otherwise I will assume that you will be prepared to be tested on anything in the chapter.

Please read chapter 6 and the Chapter 6 slides. We will discuss them in a future class.

Here are some additional notes from the 2pm class today courtesy of Michelle Klotz.