Rails check if an array exists

Question

Sorry for my probably noobish question; I recently started developing with Rails. I checked through the API, documentation, and did a bunch of searches but could not find what I was look for.

Is there a method to check to see if a specific array exists?

For example,

    array = []
    array = [2,3,4]
    if array.exists?
      puts "array exists!"
    else
      puts "No such thing!"
    end

Thanks

Answer 1

like so:

if defined?(array)

instance variables (eg @array) default to nil, so you can just test them with

if @array

Answer 2

Note: By defining your array with array = [] , your array will always exist. But if you want to check if array is an Array, you can say array.is_a?(Array)

Answer 3

Try this

a = [1,2,3]

a.any?
=> true

a.clear

a.any?
=> false

Answer 4

Hi fellas i´m newbie at Ruby on Rails but this is the most simple way:

if (defined?(array))
   puts "array exists!"
else
   puts "No such thing!"
end