How can I check if a lua table contains only sequential numeric indices?

Question

How can I write a function that determines whether it\'s table argument is a true array?

isArray({1, 2, 4, 8, 16}) -> true
isArray({1, \"two\", 3, 4, 5}) ->         


        

Answer 1

EDIT: Here's a new way to test for arrays that I discovered just recently. For each element returned by pairs, it simply checks that the nth item on it is not nil. As far as I know, this is the fastest and most elegant way to test for array-ness.

local function isArray(t)
  local i = 0
  for _ in pairs(t) do
    i = i + 1
    if t[i] == nil then return false end
  end
  return true
end