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

By "true array", I suppose you mean a table whose keys are only numbers. To do this, check the type of every key of your table. Try this :

function isArray(array)
    for k, _ in pairs(array) do
        if type(k) ~= "number" then
            return false
        end
    end
    return true --Found nothing but numbers !
end