1. Computer Science 1 Get out your notebook. 9-8-2016
Break down a program
Generic Program outline
First Dry Run
Write a Program from Scratch

2. Breaking down the program.
Math
:= ‘Is assigned the value of…’ * / + - ()
Sqr() for squaring
Sqrt()
Can’t use ^
Order of operations
{Mr. Smith}
{Sample Tax Program}
{2/1/08}
Program first;
Uses
crt;
Const
TAX=0.05;
Var
price, totalCost:real;
numberOfItems:integer;
Begin
clrscr;
writeln(‘Please enter the price of the item’);
readln(price);
writeln(‘How many would you like to buy?’);
readln(numberOfItems);
totalCost:= numberOfItems*price*(1+TAX);
writeln(‘Price = ‘, price:10:2);
writeln(‘Number of items =‘, numberOfItems);
writeln(‘The total cost = ‘, totalCost:10:2);
End.
Breaking down the program.
Begin
Every begin has an end.
Indent between the begin and end.
Eventually programs will have several begins and ends.
{} Comments // Single Line Comments
On each program include: Your Name, Short Description of your program, and the date
More on writeln
You can show several values,
Strings, variables, or expressions (it will show the answer)
but you need to put a , between them.
Strings: put inside ‘’
Variables/Expressions, no ‘’
Formatting :10 uses 10 spaces for strings, characters, integers
Formatting:10:2
For reals, sets 10 spaces t be used, 2 of them are for values to the right of the decimal point.
Writeln
Write Line
Shows information on the screen and goes down to the next line.
‘Shows every character in ‘’’
To show and ‘, you enter ‘’ (Two apostrophes)
Identifier Names:
Start with a character.
Then can have characters and/or numbers
No spaces, punctuation or reserved words.
Also, for this version of Pascal. It can’t match the saved name of the program
Var section used to declare variables.
Real: Have decimals
Integer: No decimals
Char: single characters
String: A bunch of characters. (Names words, sentences up to 256 characters)
Uses: Ties to libraries of commands.
Const:
Used to declare constants.
Translate to Pascal
Ans = (1/2)bh
Ans =πr2
Ans = 3a + 4b
Ans = 1/r1 + 1/r2
Ans = 4/3 πr3
Clrscr
Clearscreen.
Must have the uses crt in order to use the clrscr command.
Readln;
Used for getting information from the user.
It stops the program from running and waits for the enter key to be hit.
If you enter a value before hitting enter, it places that value in the variable.
Type mismatch?
End.
The end of the program.
Note this line ends with a .

3. Getting Names Program sample2; var begin end. name:string;
writeln(‘Please enter your name.’);
readln(name);
writeln(‘Hello ‘, name,’ welcome back!’);
readln;
end.

4. Computer Science 1 Learning
Review
Be able to ‘Dry Run’ a program.
Be able to fix a poorly written program.
Given a problem, be able to write a program to solve the problem.
Get out your notebooks.

5. Review Describe the following Reserved word Writeln Readln Begin Var
Const
uses
Const
Type {} //
End
Program
:10:2
Compile

6. Put the following in order as they would appear in a program.
Var
Type
Program
Begin
Uses
End
const
Program
Uses
Const
Type
Var
Begin
end

7. General Outline of a Program
{Header information
Name
Description
Date}
Program name;
uses
const
type
Procedures/functions
var
begin //main body
end.
Leave these sections off, if you are not using them.

8. Dry run 1 (What do you think the following program does?)
{Mr. Smith's Sample Program}
{Dry Run #1}
{9/7/12}
program DryRunTest;
uses
crt;
var
a,b,c:integer;
begin
clrscr;
a:= 8;
b:= 6;
c:= a+b;
writeln(a, b, c);
b:= b + 2*a;
a:= a + 7;
end.
Dry run 1 (What do you think the following program does?) a b c
Screen

9. Your next program
Write a program that will display your home address as it would on an envelope.
Push: Let the user enter some or all of the information, and have your program format it.
Write a mad-lib program
Have the user enter at least 4 pieces of information.
Noun, Adverb (honestly), Adjective (messy), Verb, Geographical location, …
The computer will generate the mad-lib
Here is a sample website
Write a program that shows a poem or song. Can be an original work. Include space as appropriate.
Push: Look up for..do, or repeat..until to have your program repeat the song several times.
Push: Use the Pascal tutorial to add color etc.