[iGCS] Array

[iGCS] Array

Objectives

• What is array and the terminology related

• Array in pseudocode

• Array in Python

Imagine you need to have a health monitor program

• Enter name of the user

• Enter body temperature in day 1

• Enter body temperature in day 2

Open Ended

Write Pseudocode for the application mentioned before!

Same application, but 14 days...

• The data need to be stored (for future use)

• And maybe longer than 14 days....

• For loop can help

So if we use for loop, it should be something like:

FOR i <- 1 TO 14:

⠀INPUT day-i

NEXT i

Since the day-i is repeating, but can we do that?

Array

• Array is a collection of variable

• All of them are same data type

• And similar kind of data

Declare array

# Both of the followings will declare an array of n elements

DECLARE temperatures[0..n-1]

DECLARE temperatures[1..n]

Note:

Array size, or number of element, is fixed once it is declared

Accessing the array elements

We use [square brackets] to indiciate which element we are accessing:

DECLARE temperatrues[0..13]

temperatures[0] = 37.5

# So the above example, we called "0" is the index of the first element of the array

A few key terms:

• index: the location of an item in an array. In Python index starts from 0

• size: how many items in the array, array size is fixed

• element: each item in the array

Open Ended

Write the Pseudocode to declare an array of "scores", which consisted of 24 elements.

Open Ended

DECLARE scores[0..23]

Write the Pseudocode to assign 100 to first score.

Python array Practice

• Declare an array for 14 temperatures (float) data

• Write a for-loop to enter those temperatures data, with proper prompt

• Write another for-loop to calculate the average of those inputted temperature