Arrays

Question 1

array

Answer 1

a data structure that can store multiple items of data, called elements, which are all the same data type, under the same identifier

Question 2

elements

Answer 2

an item of data in an array at a particular index

they are all the same data type

they are stored under one identifier

Question 3

How is an array created?

Answer 3

by specifying the elements stored in the array

this is called declaring the array

e.g.
array names = [“Alice”, “Catherine”]
array scores = [10, 13, 17]

Question 4

indexes

Answer 4

the location of an element in an array

Question 5

two dimensional arrays

• what they are
• how they are used

Answer 5

an array structured like a table

each element has two indices to indicate its position

an array of arrays which forms a matrix

e.g.
an array with 5 rows and 4 columns would be declared like this:
array scores [5, 4]

data would be added like this:
scores [3,3] = 15

Question 6

A student recorded their resting pulse three times a day (8am, 12:30pm and 8pm) for four days and stored the data in a 2D array:

0/day 1: 0 = 65 1 = 73 2 = 70
1/day 2: 0 = 65 1 = 75 2 = 68
2: 0 = 70 1 = 80 2 = 65
3: 0 = 68 1 = 79 2 = 69

a) to output the pulse rate at noon on day 1 the student wrote the following code:
print(pulse[0, 1])

i) state the pulse rate output from this statement [1]
ii) write the code to output the pulse rate in the evening on day 3 [1]

b) write the code that would output the average pulse rate for each day [5]

Answer 6

a) i) 73
a) ii) print(pulse[2, 2])

b) 
for day = 0 to 3
    total = 0
    for time = 0 to 2
        total = total + pulse[day, time]
    next time
    print("Average = " + total/3)
next day

Question 7

A student has stored the first name and surname of each of their friends (in that order) into a 2D array named ‘friends’.
Write an algorithm that would allow the student to enter a friends name and check whether that friend is in the array. [5]

Answer 7

firstName = input("Please enter the first name")
lastName = input("Please enter the last name")

index = 0
found = false

while found == false AND index <= friends.length - 1
if friends[index, 0] == firstName and friends[index, 1] ==
lastName then
found == true
endif
index = index + 1
endwhile

if found == true then
    print("This friend is in the array")
else
    print("This friend is not in the array")
endif