To touch every element in a 2D array, you must use nested loops. The controls the row. The inner loop controls the column.
// Example Usage: let myGrid = [ [1, 2, 3], [4, 5, 6], [7, 8, 9] ]; print2DArray(myGrid); /* Output: 1 2 3 4 5 6 7 8 9 */
Here is a typical you might see:
A 2D array is essentially an .
: The new value is the total count of all items (11 in this example). : The new value is array[2][0] + array[2][1] (9 + 8 = 17). For more detailed explanations, you can refer to the CodeHS Textbook on 2D Arrays or community discussions on platforms like Reddit r/codehs Are you running into a specific compiler error test case failure with your current code?
The primary objective of this lesson is to manipulate existing data within a 2D array. Instead of just reading the data, you must write code that changes the values stored inside the grid. 1. Nested For Loops
function swapRows(matrix, rowA, rowB) let temp = matrix[rowA]; matrix[rowA] = matrix[rowB]; matrix[rowB] = temp; return matrix; Codehs 8.1.5 Manipulating 2d Arrays
Good programming practice: if the input is null or empty, the method should probably return null or an empty array. In many CodeHS tests, the input will be valid, but including safety checks shows thoroughness.
Before coding, sketch the 2D array on paper. If arr = 1, 2, 3, 4, 5, 6 , visualize it: Row 1 2. Using Nested for Loops To manipulate every element, you need nested loops: The outer loop iterates through the rows ( r ).
Writing grid[r][c] + 5; does nothing. You must assign it: grid[r][c] = grid[r][c] + 5; (or grid[r][c] += 5; ). If you want to debug your specific code, tell me: To touch every element in a 2D array,
Remove last column:
Each of these exercises builds on the exact same nested‑loop structure you used in 8.1.5.
for (int row = 0; row < studentScores.length && !found; row++) for (int col = 0; col < studentScores[row].length && !found; col++) if (studentScores[row][col] == targetScore) found = true; // Example Usage: let myGrid = [ [1,
You need to define a method—often called fixArray or updateValue —that takes the array, the row index, the column index, and the new value.