This document discusses variables, assignment, and types in the Pascal programming language. It provides an example program that asks the user to input a number between 1 and 99, analyzes their "personality" based on that number, and ends the program. It also discusses values, variable names, assignment, statements, and operators in Pascal. Finally, it provides challenges to write programs to convert Fahrenheit to Celsius and perform basic math operations on two user-input numbers.

1. Delphi and Pascal
Variables, Assignment and
Types

2. Personality Tester
var
yournumber:integer;
begin
write( 'Please enter a number between 1 and 99: ');
readln(yournumber);
writeln('You entered ' , yournumber);
writeln('Performing personality analysis on your number choice …');
if yournumber < 49 then
writeln('You are truly inadequate')
else
writeln('You have delusions of grandeur');
writeln('That''s all folks');
readln;
end.

3. Values
• A basic thing – a letter or a number
• Values have TYPES
• Integers 1, 29485
• Strings “Hello world”
• Double– floating point 3.14159

4. Variables
• A variable has a value
mynumber

5. Variable names
• Can’t begin with a number
• Can’t contain spaces or other funnies
• Can’t be a keyword
– Type help() and press return
– Then type keywords in the box.
• Case doesn’t matter .. But it does!

6. Assignment
Putting a Value ‘into’ a Variable
• myVariable := 23
• myLongVariable := “Hello how’s it going”
Sometimes written with an arrow
• myVariable 23
Assignment is really a sort of COPY
Why?

7. Assignment quiz
• What’s the value of myVariable
myVariable := 22;
mySecondVariable := 13;
myVariable := mySecondVariable;
myVariable := str(myVariable);

8. Statements
• A statement is a piece of code that
Pacal can execute.
• Lots of statements make a program

9. Operators
• Operators ‘do things’ to operands
• The simplest operators are the math
+ addition 5+2
- subtraction 5-2
* multiplication 5*2
/ division 5/2
div integer division 5 div 2
mod modulo 5 mod 2

10. A useful program
• Write a Fahrenheit to Celsius converter
• The formula for the conversion is: F = 1.8 * C + 32
• To make this program work you will need to do the
following:
Get the user input with readln(variablename);
• Now you have an integer, multiply it by 1.8 and add 32
• Print the result – your answer, to the screen with
writeln(variablename)

11. Challenge
• Write a script/program that allows you to
input two numbers and calculates their:
– Product
– Sum
– Difference
– Quotient (one number divided by the other
without any remainder)
– Remainder (remainder when one is divided by
the other)