String Reversal Approaches in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to reverse the string using slicing.

DSA Python

reversed_str = original_str[1]

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

A[1:]

B[:]

C[::-1]

D[::-2]

Attempts:

3 left

💡 Hint

Common Mistakes

Using [:] returns the original string without reversing.

Using [1:] skips the first character but does not reverse.

Using [::-2] reverses but skips characters.

Using slicing with [::-1] reverses the string by stepping backwards one character at a time.

2fill in blank

medium

Complete the code to reverse the string using the reversed() function and join.

DSA Python

reversed_str = ''.[1](reversed(original_str))

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

Asplit

Bjoin

Cappend

Dreplace

Attempts:

3 left

💡 Hint

Common Mistakes

Using append() is for lists, not strings.

Using split() breaks strings into lists, not reverse.

Using replace() changes characters, not order.

The join() method combines characters from reversed() into a new reversed string.

3fill in blank

hard

Fix the error in the code to reverse the string using a for loop.

DSA Python

reversed_str = ''
for char in original_str:
    reversed_str = char [1] reversed_str

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

A/

B*

C-

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using * or - operators causes errors or wrong results.

Appending char after reversed_str does not reverse.

Concatenating the current character before the reversed string builds the reversed string step by step.

4fill in blank

hard

Fill both blanks to reverse the string using a list and the reverse() method.

DSA Python

char_list = list(original_str)
char_list.[1]()
reversed_str = ''.[2](char_list)

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

Areverse

Bjoin

Cappend

Dsort

Attempts:

3 left

💡 Hint

Common Mistakes

Using sort() changes order but sorts alphabetically, not reverses.

Using append() is for adding elements, not reversing.

Using join() before reverse() will not reverse the string.

reverse() reverses the list in place, and join() combines the list into a string.

5fill in blank

hard

Fill all three blanks to reverse the string using recursion.

DSA Python

def reverse_str(s):
    if len(s) [1] 0:
        return ''
    else:
        return reverse_str(s[[3]]) + s[[2]]

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

A==

B0

C1:

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using != in base case causes infinite recursion.

Using -1 as index returns last char, but recursion needs first char then rest.

Incorrect slicing causes errors or wrong output.

Base case checks if string is empty (length 0). Then return recursive call on rest plus first char.