- The array
arr is a \(2 \times 3\) grid where arr[0][2] is the third element of the first row (\(3\)) and arr[1][2] is the third element of the second row (\(6\)). - The variable
val is calculated as the sum of these two elements: \(\text{val} = 3 + 6 = 9\). - The final output of the code snippet is \(\boxed{9}\).
Explanation
- Analyzing the 2D Array Structure and Indexing
The given code snippet defines a two-dimensional array of integers named arr with two rows and three columns:
\[\text{arr} = \begin{pmatrix} 1 & 2 & 3 \ 4 & 5 & 6 \end{pmatrix}\]
In C++, array indexing is zero-based. This means that the rows are indexed as 0 and 1, and the columns are indexed as 0, 1, and 2. To find the output of the code, we first identify the elements being accessed:
- The expression
arr[0][2] refers to the element in the first row (index 0) and the third column (index 2). Looking at the first row {1, 2, 3}, the element at index 2 is 3. - The expression
arr[1][2] refers to the element in the second row (index 1) and the third column (index 2). Looking at the second row {4, 5, 6}, the element at index 2 is 6.
- Calculating the Final Value
Now that we have identified the values at the specified indices, we can proceed to calculate the value of the variable val:
\[\text{val} = \text{arr}[0][2] + \text{arr}[1][2]\]
\[\text{val} = 3 + 6 = 9\]
Thus, when the code executes cout << val;, the output printed to the console will be 9. Matching this with the provided options:
The correct option is 9.
Examples
Understanding 2D arrays is foundational for handling data in grids, such as in game development (e.g., a chessboard or pixel map), image processing, or scientific simulations. For example, if you were building a simple game where a character moves on a grid, you could represent the grid as a 2D array, where each coordinate (row, col) stores information about the terrain or objects present at that location. Mastering array indexing allows you to efficiently access, update, and process this information as needed.