Functional way to check if array of numbers is sequential

Question

Let\'s say that an array is sequential when each successful element has the value of previous element + 1. Suppose I have an array of numbers like {5,6,7,

Answer 1

Same as: make sure array is sequential in C#

Answer there:

if you're sure that the array is sorted and has no duplicates, you can just check:

array[array.Length - 1] == array[0] + array.Length - 1