Syed: 1D Array

What is an Array?

• A data structure consisting of a collection of elements grouped under a single name.

• 1. A collection of functions grouped under a single name.

• 1. A variable that can store multiple data types simultaneously.

• 1. A programming method used to iterate through data elements.

Answer explanation

A data structure consisting of a collection of elements grouped under a single name.

Can an Array store values of different datatypes?

(a)  

• Yes

• No

• Maybe

• Not sure

• Possibly

Answer explanation

No, an Array cannot store values of different datatypes as it requires all elements to be of the same type.

Guess the output.

names=["Lisa","Jane","William"]

print(names[1])

• Lisa

• Jane

• William

• Error

Answer explanation

The correct answer is Jane because names[1] accesses the element at index 1 in the list, which is 'Jane'.

What is the ouput?

DECLARE nums: ARRAY[0:4] OF INTEGER

nums ← [5, 10, 15, 20, 25]

OUTPUT(nums[2])

• 5

• 10

• 15

• 25

Answer explanation

The output is 15 because nums[2] refers to the element at index 2 in the array nums, which is 15.

If an array data contains five elements [5, 3, 7, 1, 9], what is the value of data[3]?

• 5

• 3

• 7

• 1

Answer explanation

The value of data[3] is 1 because array indexing starts at 0, so data[3] refers to the fourth element in the array which is 1.

Which pseudocode initializes an array of size 10.

• DECLARE nums: ARRAY[0:9] OF INTEGER

• DECLARE nums: ARRAY[1:10] OF INTEGER

• DECLARE nums: ARRAY[1:9] OF INTEGER

• DECLARE nums: ARRAY[0:10] OF INTEGER

Answer explanation

The correct pseudocode to initialize an array of size 10 is DECLARE nums: ARRAY[0:9] OF INTEGER or DECLARE nums: ARRAY[1:10] OF INTEGER.

How many elements are in the following array?

DECLARE items: ARRAY[0:4] OF STRING

items ← ["apple", "banana", "cherry", "date", "elderberry"]

Mathematical Equivalence

ON

What is the index of the first element in most programming languages?

• 0

• 1

• 2

• 8

Answer explanation

In most programming languages, the index of the first element is 0, making 0 the correct choice.

What does the following pseudocode print?

DECLARE numbers: ARRAY[0:3] OF INTEGER

numbers ← [2, 4, 6, 8]

OUTPUT(numbers[1])

• 2

• 4

• 6

• 8

Answer explanation

The pseudocode prints the value at index 1 of the 'numbers' array, which is 4. Therefore, the correct answer is 4.

How do you change the third element of an array, myArray to 100?

• myArray[2] = 100

• myArray[3] = 100

• myArray[1] = 100

• myArray[4] = 100

Answer explanation

To change the third element of an array myArray to 100, you should use myArray(2) = 100 as array indexing starts from 0.