for(let r = 0; r < grid.length; r++) for(let c = 0; c < grid[0].length; c++) // Note: Using grid[0].length works if it's a rectangular grid Use code with caution. 3. Apply the Logic
double columnAvg = (double) columnTotal / studentScores.length; System.out.println("Average for Test " + (col + 1) + ": " + columnAvg);
Let's assume the task is to write a function that takes a 2D array and doubles every element inside it. javascript Codehs 8.1.5 Manipulating 2d Arrays
public class ArrayManipulator public static int[][] doubleArray(int[][] nums) if (nums == null
CodeHS 8.1.5 often requires you to change values only if they meet certain criteria. for(let r = 0; r double columnAvg =
Write a method named doubleArray that takes a 2D integer array as a parameter and where each element is twice the original element.
// Search for a perfect score of 100 int targetScore = 100; boolean found = false; // Search for a perfect score of 100
| Mistake | Consequence | Fix | |---------|------------|-----| | Using nums[row].length in the outer loop condition | Compiler error because row is out of scope | Use nums.length for row count | | Forgetting that rows can have different lengths | ArrayIndexOutOfBoundsException if you assume square | Use nums[row].length for columns per row | | Returning the original array instead of a new one | Changes affect the caller’s original when not intended | Create a new array and fill it | | Off‑by‑one errors: <= vs < | IndexOutOfBoundsException | Always use < for length | | Null pointer exception when input is null | Crash | Add a null check at the beginning |
To solve for Row 2, you must first calculate the total number of elements in the 2D array. Since sub-arrays can have different lengths (jagged arrays), you need a nested loop. totalElements = ; i < array.length; i++) < array[i].length; ++) totalElements++;