Procedures & Functions (Cambridge (CIE) IGCSE Computer Science): Revision Note

Pseudocode

PROCEDURE CalculateArea(Length : INTEGER, Width : INTEGER)
    DECLARE Area : INTEGER
    Area ← Length * Width
    OUTPUT "The area is ", Area
ENDPROCEDURE

Python

def ageCheck(age):
    if age > 18:
        print("You are old enough")
    else:
        print("You are too young")

Pseudocode

CALL DefaultLine
CALL CalculateArea(5, 3)

Python

ageCheck(21)

# Procedure definition for the main menu
def main_menu():
    # Outputs the options
    print("1. Addition") 
    print("2. Subtraction")
    print("3. Multiplication")
    print("4. Division")
    print("5. Exit")

    # Asks the user to enter their choice
    choice = int(input("Enter your choice: ")) 
    if choice == 1: 
        addition() 
    elif choice == 2:
        subtraction()
    elif choice == 3:
        multiplication()
    elif choice == 4:
        division()
    elif choice == 5:
        exit_program()

# Procedure definition for addition
def addition(): 
    num1 = int(input("Enter the first number: "))
    num2 = int(input("Enter the second number: ")) 
    print("Result:", num1 + num2) 

# Procedure definition for subtraction
def subtraction():
    num1 = int(input("Enter the first number: "))
    num2 = int(input("Enter the second number: "))
    print("Result:", num1 - num2)

# Procedure definition for multiplication
def multiplication():
    num1 = int(input("Enter the first number: "))
    num2 = int(input("Enter the second number: "))
    print("Result:", num1 * num2)

# Procedure definition for division
def division():
    num1 = int(input("Enter the first number: "))
    num2 = int(input("Enter the second number: "))
    if num2 != 0:
        print("Result:", num1 / num2)
    else:
        print("Error: Division by zero is not allowed.")

# Procedure to exit the program
def exit_program():
    print("Exiting the program. Goodbye!")
    exit()

# Main program
while True:  # Loop to continuously show the menu until the user chooses to exit
    main_menu()

Pseudocode

FUNCTION CalculateArea(Length : INTEGER, Width : INTEGER) RETURNS INTEGER
    DECLARE Area : INTEGER
    Area ← Length * Width
    RETURN Area
ENDFUNCTION

// Output the value returned from the function
OUTPUT CalculateArea(5, 3)

Python

def squared(number):
    result = number ** 2
    return result

# Output the value returned from the function
print(squared(4))

# Function definition, length and width are parameters
def calculate_area(length, width):
    area = length * width  # Calculate area
    return area  # Return area

# Main program #1
length = int(input("Enter the length: "))
width = int(input("Enter the width: "))
print(calculate_area(length, width))  # Calls the function and prints the result

# Main program #2
length = int(input("Enter the length: "))  # Input for length
width = int(input("Enter the width: "))  # Input for width
calculated_area = calculate_area(length, width)  # Stores the result of the function in a variable
print("The area is " + str(calculated_area) + " cm^2")  # Outputs the result with a message