Intro & Revision

Variables

• Are memory addresses in a computer used to store information so that the CPU may use it, for example, $i=0$
• Variables are temporary. They are usually collected by a garbage collector once their purpose is complete.
  • Constants are variables that are immutable - they do not change. For example, $pi=3.14$
  • Global and Local variables. Globals have a global scope (main module). Local variables are only acessible in their own module.
    See below; code snippet.

const pi = 3.1415 //constant
let temp_local = 0 //variable - in js, let makes it local
var temp_global = 0 //global

Pseudocode

• Make sure to include line numbers
• Used to plan out a program logically (in our mind), breaking down complex programs into step by step logical thingos for human readable

Data types

• For syllabus
  • Int
  • Float
  • Str
  • Boolean

Types of operators

• Arithmetic - + * -*
• Conditional/relational - > < == !=
• Logical - and or not

Pseudocode Example

#1

The 'Wilson' Standard (Y10, Mr Wilson)

BEGIN
	INPUT(num1)
	INPUT(num2)
	total <= num1 + num2
	OUPUT(total)
END

The 'Chilson' Standard (Y11, Mr Chillapa)

BEGIN
	Num1, Num2, Total are float
	INPUT <= Num1, Num2
	READ <= Num1, Num2
	Total <= Num1 + Num2
	Output <= Total
END

#2

BEGIN
	num1, num2, num3 are float
	INPUT <= num1, num2, num3
	READ <= num1, num2, num3
	IF (num1 > num2) AND (num1 > num3) THEN
		OUTPUT <= 'The big boy number is the first one'
	ELSE IF (num2 > num1) AND (num2 > num3) THEN
		OUTPUT <= 'The big boy number is the second one'
	ELSE
		OUTPUT <= 'The big boy number is the first one'
	ENDIF
END

#3 - Python

a = float(input('First: '))
b = float(input('Second: '))
c = float(input('Third: '))

if (a > b) and (a > c):
    print('First is the largest')
elif (b > a) and (b > c):
    print('Second is the largest')
elif (c > a) and (c > b):
    print('Third is the largest')
else:
	print('They are all of equal magnitude from the digit zero.')