CPS 1 - Spring, 1997 - Ramm 1/20/97 #2

Chapter 1. An Intro to Programming: Coding Decision Trees

What is a program?/What is programming?
- creating such recipes is called programming
Why program?
- re-use
A Problem Domain: The Decision Tree
- Car won't start

What kinds of questions should you be able to answer?

Can't get car's engine to run; what is the problem?
was car just running and quit now?	yes	is gas gauge on empty?	yes	get gas
			no	call tow truck
	no	does engine crank?	yes	check gas
			no	check battery

Limitations of Decision Tree approach
- May be worth it if used many times
How to implement: Pascal Program
- Need to start with simpler things
I like to teach by using examples:
program Greeting; begin writeln(' Hello Folks'); writeln('Hope things are OK'); writeln('\\\\**********////'); readln;
end.
What do we do with it?
- Turbo Pascal is an integrated collection of programs (or system) to facilitate all of this
Format or Structure of a Pascal Program
simplest form:
- END.
More program elements/definitions
- readln;
EXECUTE in order unless told otherwise
Syntax/Data
- Examples with syntax and nonsense errors
Reading and Storing Data
- To set up:
  VAR
  msg1: string; readln(msg1);
Example:
program echo; var msg1:string; begin readln(msg1); writeln(msg1); readln;
end.
More complicated examples: Using more than one variable.