# How to get diagonal elements in a 2-D matrix

This is a snippet of a for loop that shows how to get the diagonal elements in a 2-D matrix. I thought it was an interesting demo of how a for loop is used with two indices to get the numbers in the diagonal of a matrix.

```
function diagonal(arr) {
let arr2 = []
for (let i=0; i<arr.length; i++) {
arr2.push(arr[i][i])
}
return arr2
}
diagonal([
[4, 4, 4, 4],
[2, 4, 9, 8],
[5, 4, 7, 7],
[6, 4, 1, 0]
]) // [ 4, 4, 7, 0 ]
```