How to find the maximum number of repetitions in an array of consecutive ones?

Question

JavaScript

There is an array of this kind. It is necessary to calculate the maximum number of repeating elements in a row. For example, in this case, you need to calculate how many maximum 1 goes in a row (there are 4 repetitions).
const arr = [1, 5, 99, 1, 1, 1, 2, 8, 1, 1 ,1 ,1]

Answer 1

Math.max(...arr.reduce((acc, n, i, a) => (
  n !== a[i - 1] && acc.push(0),
  acc[acc.length - 1]++,
  acc
), [ 0 ]))