Circularly Sorted Array.js

/*
Description:
Write a method, isCircleSorted(int[] A) (Java, JavaScript), or Array#circularly_sorted? (Ruby) that determines if A is circularly sorted. An Array is circularly sorted if the elements are sorted in ascending order, but displaced, or rotated, by any number of steps.

For Example:

// True:
isCircleSorted([2,3,4,5,0,1]);
isCircleSorted([4,5,6,9,1]);
isCircleSorted([10,11,6,7,9]);
isCircleSorted([1,2,3,4,5]);
isCircleSorted([5,7,43,987,-9,0]);


// False:
isCircleSorted([4,1,2,5]);
isCircleSorted([8,7,6,5,4,3]);
isCircleSorted([6,7,4,8]);
isCircleSorted([7,6,5,4,3,2,1]);
*/
function isCircleSorted( arr ){
    let cnt = 0;
    for (let i = 0; i < arr.length; i++) {
        if (arr[i] > arr[(i + 1) % arr.length]) {
            cnt++;
        }
    }
    return cnt === 1;
}