Test: 2D Arrays - 1 - EmSAT Achieve MCQ

In Python, a 2D array is typically represented as a list of lists. It is a data structure that allows you to store elements in a grid-like format with rows and columns. Each inner list within the main list represents a row of elements, and the length of each inner list determines the number of columns in the 2D array.

A 2D array in Python is represented as a list of lists. Each inner list represents a row in the array.

The shape of a 2D array with n rows and m columns is represented as (n, m).

Appending new rows to a 2D array is not a valid operation. The number of columns must be consistent across all rows.

The numpy module provides functions for working with 2D arrays in Python.

Accessing an element in a 2D array with n rows and m columns takes constant time, O(1), as the indexing operation is direct.

The code snippet accesses the element at the second row (index 1) and third column (index 2) of the 2D array. The value is 6.

The code snippet uses the len() function to get the length of the second row of the 2D array. The length is 4.

The code snippet accesses the last element of the last row in the 2D array. The value is 6.

The code snippet accesses the first element of the second-to-last row in the 2D array. The value is 3.

The code snippet calculates the sum of all elements in the 2D array. The sum will be 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45.

The code snippet prints a sublist of the 2D array starting from the second row. The output will be [[4, 5, 6]].

The code snippet uses a list comprehension to extract the second element from each row of the 2D array. The output will be [2, 5, 8].

The code snippet uses a list comprehension to extract the diagonal elements from the 2D array. The output will be [1, 4, 6].

The code snippet uses a nested list comprehension to flatten the 2D array into a 1D list. The output will be [1, 2, 3, 4, 5, 6].