Arrays vs Other Data Structures When to Choose Arrays in DSA Python - Interactive Comparison Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an array of size 5 initialized with zeros.

DSA Python

arr = [[1]] * 5
print(arr)

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ANone

B0

C1

D''

Attempts:

3 left

💡 Hint

Common Mistakes

Using None instead of 0 will create an array of None values.

Using 1 will create an array of ones, not zeros.

The array is initialized with zeros by using 0 inside the list multiplied by 5.

2fill in blank

medium

Complete the code to access the third element of the array.

DSA Python

arr = [10, 20, 30, 40, 50]
print(arr[[1]])

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A2

B1

C3

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using index 3 will access the fourth element, not the third.

Using index 1 will access the second element.

Arrays start at index 0, so the third element is at index 2.

3fill in blank

hard

Fix the error in the code to append an element to the array.

DSA Python

arr = [1, 2, 3]
arr.[1](4)
print(arr)

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Aextend

Badd

Cinsert

Dappend

Attempts:

3 left

💡 Hint

Common Mistakes

Using add() causes an error because lists do not have add method.

Using insert() requires two arguments, so it will cause an error here.

The correct method to add an element at the end of a list (array) is append.

4fill in blank

hard

Fill both blanks to create a list of squares for numbers 1 to 5, but only include squares greater than 10.

DSA Python

squares = [x[1]2 for x in range(1, 6) if x[2]3]
print(squares)

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A**

B%

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using % instead of ** will calculate remainder, not square.

Using < instead of > will filter wrong numbers.

Use ** to square the number and > to filter numbers greater than 3.

5fill in blank

hard

Fill all three blanks to create a dictionary with keys as uppercase letters and values as their ASCII codes, but only for letters with ASCII code greater than 65.

DSA Python

result = { [1]: [2] for letter in ['a', 'B', 'C', 'd', 'E'] if ord(letter) [3] 65 }
print(result)

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Aletter.upper()

Bord(letter)

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using letter instead of letter.upper() will keep keys in original case.

Using < instead of > will filter wrong letters.

Use letter.upper() as keys, ord(letter) as values, and filter letters with ASCII code greater than 65.