For example, the square matrix is shown below:

```
1 2 3
4 5 6
9 8 9
```

The left-to-right diagonal =1 + 5 + 9 = 15. The right to left diagonal = 3 + 5+ 9 = 17. Their absolute difference is **|15–17| = 2 .**

**Function description**

Complete the ** diagonalDifference** function in the editor below. It must return an integer representing the absolute diagonal difference.

diagonalDifference takes the following parameter:

- arr: an array of integers .

**Input Format**

The first line contains a single integer, ** n** , the number of rows and columns in the matrix

**.**

*arr*Each of the next ** n** lines describes a row,

**, and consists of**

*arr[i]***space-separated integers**

*n***.**

*arr[i][j]***Constraints**

***. — 100 ≤ arr[i][j] ≤ 100*

**Output Format**

Print the absolute difference between the sums of the matrix’s two diagonals as a single integer.

**Sample Input**

```
11 2 4
4 5 6
10 8 -12
```

**Sample Output**

```
15
```

**Explanation**

The primary diagonal is:

```
11
5
-12
```

Sum across the primary diagonal: 11 + 5–12 = 4

The secondary diagonal is:

```
4
5
10
```

Sum across the secondary diagonal: 4 + 5 + 10 = 19 Difference: |4 –19| = 15

**Note:** |x| is the absolute value of x

## Solution

Using JavaScript:

```
**function** diagonalDifference(arr) {
** var** n = arr.length;
**var** d1 = 0;
**var** d2 = 0;
** for**(**var** i=0; i<n; i++){
** for**(**var** j=0; j<n; j++){
*// finding the sum of primary diagonal*
** if**(i === j) {
d1 += arr[i][j];
}
*// finding the sum of secondary diagonal*
** if**(i + j === n - 1){
d2 += arr[i][j];
}
}
}
**return** Math.abs(d1 - d2);
}
```