Successfully reported this slideshow.
Upcoming SlideShare
×

Pascal names and types

• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Pascal names and types

1. 1. Delphi and Pascal Variables, Assignment and Types
2. 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. 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. 4. Variables • A variable has a value mynumber
5. 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. 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. 7. Assignment quiz • What’s the value of myVariable myVariable := 22; mySecondVariable := 13; myVariable := mySecondVariable; myVariable := str(myVariable);
8. 8. Statements • A statement is a piece of code that Pacal can execute. • Lots of statements make a program
9. 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. 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. 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)