Check if array of integers increments in Ruby

Question

I want to check if an arrays values once sorted are incrementing by 1

For example

[1, 2, 3, 4, 5] = TRUE
[1, 2, 8, 9, 10] = FALSE

Any suggestions are much appreciated

Answer 1

array = [1,2,4,3]
array.sort.each_cons(2).all? { |x,y| y == x + 1 }

Answer 2

This one doesn't require sort.

a = [2, 8, 1, 9, 10]
b = a.dup
x = b.delete(b.min)
nil while b.delete(x+=1)
b.empty?