J277 - 2.2 - Use of Arrays up to 2D

What is an array in programming?

• A data structure that stores elements in a key-value pair format.

• A data structure that stores a collection of elements, typically of the same data type, in a contiguous memory location.

• A function that performs operations on a set of numbers.

• A loop that iterates over a sequence of numbers.

Which of the following is a valid way to declare a one-dimensional array in Python?

• `array = [1, 2, 3, 4]`

• `array = (1, 2, 3, 4)`

• `array = {1, 2, 3, 4}`

• `array = <1, 2, 3, 4>`

How do you access the third element in a one-dimensional array named `numbers` in Python?

• `numbers[2]`

• `numbers[3]`

• `numbers[1]`

• `numbers[0]`

What is the result of the following operation on a 1D array `arr = [5, 10, 15, 20]`: `arr[1] = 25`?

• `[5, 10, 15, 20]`

• `[5, 25, 15, 20]`

• `[5, 10, 25, 20]`

• `[25, 10, 15, 20]`

Which of the following best describes a two-dimensional array?

• A list of lists where each element is a list.

• A single list with multiple data types.

• A dictionary with keys and values.

• A set of unique elements.

How do you access the element in the second row and third column of a 2D array `matrix` in Python?

• `matrix[1][2]`

• `matrix[2][3]`

• `matrix[3][2]`

• `matrix[2][1]`

What is the result of the following operation on a 2D array `matrix = [[1, 2], [3, 4]]`: `matrix[0][1] = 5`?

• `[[1, 2], [3, 4]]`

• `[[1, 5], [3, 4]]`

• `[[5, 2], [3, 4]]`

• `[[1, 2], [5, 4]]`

In a 2D array, how would you describe the operation of iterating over each element in the array?

• Nested loops where the outer loop iterates over rows and the inner loop iterates over columns.

• A single loop iterating over all elements.

• A recursive function call.

• A function that returns the length of the array.