Given the following assignment of a variable: LS = [1, 9, 2, 8, 3, 7, 5, 4]…
2023
Given the following assignment of a variable: LS = [1, 9, 2, 8, 3, 7, 5, 4] print(LS[::-2] + LS[::-2]) What will be the output of the following?
- A.
[5, 3, 2, 1, 9, 8, 7, 4]
- B.
[1, 2, 3, 5, 4, 7, 8, 9]
- C.
[4, 7, 8, 9, 4, 7, 8, 9]
- D.
[9, 8, 7, 4, 5, 3, 2, 1]
Attempted by 1933 students.
Show answer & explanation
Correct answer: C
Key insight: LS[::-2] starts at the last element and takes every second element moving left.
Indices chosen (from left-based indexing): 7, 5, 3, 1.
Values at those indices: 4, 7, 8, 9 → so LS[::-2] = [4, 7, 8, 9].
Concatenate the slice with itself: [4, 7, 8, 9] + [4, 7, 8, 9] = [4, 7, 8, 9, 4, 7, 8, 9].
Final output: [4, 7, 8, 9, 4, 7, 8, 9]
This result matches the provided option text [4, 7, 8, 9, 4, 7, 8, 9].