Intro To Pseudocode #

Pseudocode is a language designed by the IB to help you focus on the logic of programming, without having to think too much about syntax. Although it’s designed to be handwritten, we have a handy website that can compile and run pseudocode.

💻 Choose one of these two compilers you can use for pseudocode:

This compiler is more forgiving. I suggest you start here. Careful, because it will allow you to use Python syntax. Don’t fall into that trap!

This pseudocode compiler is more strict, and won’t run at all if you don’t use the right syntax.

👾 💬 FYI

The more strict compiler does not supply any error messages. If your program isn’t running, you can visit the debugging page to help you troubleshoot.

Variables #

In Pseudocode, all variable names must be written with capital letters.

Use a single = for variable assignment. Comments are created using //

X = 1 //integer
NAME = "Freddy" //string
RAINING = false //boolean

Input/Output #

  NAME = input("What is your name?")  
  output "It's lovely to meet you, ",NAME

Practice #

💻 Write pseudocode to convert a given temperature from celcius to fahrenheit. The forumula for calculating fahrenheit is (temp x 1.8) + 32

Here is an example interaction:

Input a temperature in Celcius:
>>> 28
28 degrees in Celcius is 82.4 degrees in Fahrenheit

Conditional Statements #

In Pseudocode, conditional statements follow the format if _______ then or else if ______ then. After the statement, you end the conditional with end if. A single = is used for comparison (in addition to a variable assignment).

QUANTITY = input("How many hamburgers do you want?")
 
if  QUANTITY >= 10  then
   PRICE = 2.50
else if  QUANTITY <= 9  AND  QUANTITY >= 5  then
   PRICE = 3.00
else if QUANTITY = 1 then
   PRICE = 3.50
else
   PRICE = 4.00
end if // this is required

Practice #

You can determine someone’s generation using the following formula:

Here is an example interaction:

What year were you born?
>>> 1995
You are a Millenial. I bet you love avocado toast.

Nested Conditionals #

LEGS = input("Enter the number of legs the animal has: ")
FUR = input("Does the animal have fur? (yes/no)")
FLY = input("Can the animal fly? (yes/no)")

TYPE = ""

if LEGS = 4 then
    if FUR = "yes" then
        if FLY = "yes" then
            TYPE = "A flying mammal"
        else
            TYPE = "A mammal"
        end if
    else
        TYPE = "A reptile"
    end if
end if
output "The animal is: ", TYPE

Practice #