Why is cutting an array out of range not returning nil?

Question

The ruby documentation says that when trying to "cut" an array using an invalid index it will return nil, so because I always get a number array in the index after the last valid index?

array = [0, 1, 2]

# retornando um array vazio como esperado
p array[2,0] # []

# o índice 3 não existe então por que ele retorna '[]'?
p array[3,0] # []

# fora do intervalo retorne 'nil'
p array[4,0] # nil

Answer 1

The method you are calling is this array[start, length].

The documentation says:

If start == self.size and length >= 0, Returns a new Empty Array.

That is, if start is the size of the array and length is greater than or equal to zero, so it returns a new empty array.