# CHANGE THIS ARRAY TO CUSTOMIZE TEST
# this default array was grabbed from the instructions
original_array = [[1,2,[3]],4]

def flatten_array(array)
  temp_array = []
  # loop through provided array
  array.each do |item|
    # check if the given index is an array
    if item.class == Array
      # if so, run parent function on this item ---> RECURSIVE
      arr = flatten_array(item)
      # push each item to temp_array
      arr.each do |i|
        temp_array.push(i)
      end
    else
      # if item is not an array, push directly to temp_array
      temp_array.push(item)
    end
  end
  return temp_array
end

# demonstration
# run "ruby main.rb" in the terminal to execute
new_array = flatten_array(original_array)
p new_array