Codehs 8.1.5 Manipulating 2d Arrays ^hot^ — Direct & Original

Write a method swapColumns(int[][] arr, int colA, int colB) .

In the previous lessons, you learned how to create and access elements in 2D arrays (also known as matrices). In 8.1.5, you will go a step further: you will data inside 2D arrays. This is a critical skill for games (grids), data tables, image processing, and more. Codehs 8.1.5 Manipulating 2d Arrays

If you swap elements in the same loop where you iterate, you may double-swap. For column swaps, simply loop through rows; don't loop twice. Write a method swapColumns(int[][] arr, int colA, int colB)

at the end of each sub-array with values calculated based on different rules for each row. The Core Logic The exercise centers on using a method—often called updateValue —to target a specific index and replace its content. : The final value should be the length of the entire 2D array (the number of rows). : The final value should be the total number of elements across all sub-arrays in the grid. : The final value should be the sum of the first value in row 1 last value in row 3 1. Count All Elements This is a critical skill for games (grids),

) to replace the incorrect placeholder values with specific calculated totals: : Change the last element to the length of the first array : Change the last element to the total number of elements in the entire 2D array. : Change the last element to the sum of the first value and the second-to-last value in that specific array. Key Logic for the Task Counting Total Elements

function zeroOutNegatives(matrix) for (let i = 0; i < matrix.length; i++) for (let j = 0; j < matrix[i].length; j++) if (matrix[i][j] < 0) matrix[i][j] = 0;