Flatten Array Play

flatten_without_flatten.rb

#Write some code, that will flatten an array of arbitrarily nested arrays of integers into a flat array of integers. 
#e.g. [[1,2,[3]],4] -> [1,2,3,4]. 
#Try to avoid using language defined methods like Ruby's Array#flatten.*


# This feels like it can be solved with recursion, so let's try

#Okay, I'm not sure what's going on, but I'm starving, so I'm going to pause this for now
#I don't want to leave my application sitting in limbo and risk losing everything i already answered if the page re-loads
#so I'll 'submit' for now


@flattened_array = []

def flatten_without_flattened(array_of_arrays)
  array_of_arrays.each do |inner_array|
    if inner_array.is_a?(Integer)
      @flattened_array.push(inner_array)
    elsif inner_array.is_a?(Array)
      flatten_without_flattened(inner_array)
    end
  end
  @flattened_array
end

flatten_without_flattened([[1,2,[3]],4])