Diagonal Difference | Solution | JavaScript

diagonal-difference.js

/* 
  Diagonal Difference Solution.
  sample matrix = [[1,2,3], [4,5,6], [7,8,9]]
*/ 
function diagonalDifference(arr) {
    // length of input array.
    const length = arr.length;
    let diagonal1 = 0, 
         diagonal2 = 0;
    // Looping through the array and summing the diagonals.
    for (let i = 0; i < arr.length; i++) {
        // Calculating the primary diagonal.
        diagonal1 += arr[i][i];
        // Reversing the second dimension of array to calculate secondary diagonal.
        diagonal2 += arr[length - 1 - i][i]
    }
    // return absolute difference value.
    return Math.abs(diagonal1 - diagonal2); 

}