Why Strings Are a Data Structure Not Just Text in DSA Python - Test Your Knowledge

Practice - 5 Tasks

1fill in blank

easy

Complete the code to get the first character of the string.

DSA Python

word = "hello"
first_char = word[1]

Drag options to blanks, or click blank then click option'

A<0>

B(0)

C[0]

D{0}

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses instead of square brackets

Starting index at 1

The first character of a string is accessed using square brackets with index 0.

2fill in blank

medium

Complete the code to find the length of the string.

DSA Python

word = "hello"
length = [1](word)

Drag options to blanks, or click blank then click option'

Alength

Bsize

Ccount

Dlen

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent functions like size() or length()

The len() function returns the number of characters in a string.

3fill in blank

hard

Fix the error in the code to get the last character of the string.

DSA Python

word = "hello"
last_char = word[1]

Drag options to blanks, or click blank then click option'

A[1]

B[-1]

C[5]

D[-5]

Attempts:

3 left

💡 Hint

Common Mistakes

Using positive indexes beyond string length

Using index 1 which is the second character

Using index -1 accesses the last character of the string.

4fill in blank

hard

Fill both blanks to create a dictionary with words as keys and their lengths as values.

DSA Python

words = ["apple", "banana", "cherry"]
lengths = {word[1] for word in words if len(word) [2] 5}

Drag options to blanks, or click blank then click option'

A: len(word)

B>

C==

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' instead of ':' in dictionary comprehension

Using wrong comparison operators

The dictionary comprehension uses word: len(word) to map words to their lengths, and filters words with length greater than 5.

5fill in blank

hard

Fill all three blanks to create a dictionary with uppercase words as keys and their lengths as values, filtering words longer than 5.

DSA Python

words = ["apple", "banana", "cherry"]
result = { [1]: [2] for word in words if len(word) [3] 5 }

Drag options to blanks, or click blank then click option'

Aword.upper()

Blen(word)

C>

Dword.lower()

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase instead of uppercase keys

Using wrong comparison operators

The dictionary comprehension uses word.upper() as keys, len(word) as values, and filters words with length greater than 5.