I am trying to complete the Diagonal Difference Question of Hackerrank with the following JavaScript code,

function diagonalDifference(arr) {
// Write your code here
let right = 0;
let left = 0;
const row = Math.sqrt(arr.length);
for (let i=0; i<arr.length; i=i+row){
        right+= arr[i]
        i++
}
for (let i=row; i<arr.length; i=i+row){
        left+= arr[i-1]
        i--
}

let res = Math.abs(right-left)
return res

}

However, the answer keeps coming out as wrong answer
enter image description here

Besides, I tried running this code in other IDE’s and everything else gives me the correct output

>Solution :

You are almost there, try using one loop instead

const arr = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
]

const diagonalDifference = (arr) => {
  const length = arr.length;
  let left = 0,
    right = 0;

  for (let i = 0; i < length; i++) {
    left += arr[i][i];
    right += arr[length - 1 - i][i]
  }

  console.log(Math.abs(left - right));

  return Math.abs(left - right);
}

diagonalDifference(arr)