"undefined method for integer" running a custom method in Ruby-CodePudding

I'm trying to call a method I defined earlier in the code and it gives me this error:

"undefined method `filter' for 0:Integer (NoMethodError)"

This is the code:

def descending_order(n)

  @arrNum = n.to_s.chars.map {|i| i.to_i }
  @final = [@arrNum[0]]
  
  def self.filter(arr, ind)
    if self > arr[ind]
      @final.insert(ind, self)
    else
      self.filter(arr, ind 1)
    end
  end
  
  @arrNum.each { |i| i.filter(@final, 0) }
  
  return @final
    
end

I tried everything I could think of! Thanks

CodePudding user response：

Your approach is wrong!

If your intention is to return a reverse sorted array of a given number then the code snippet should be:

def descending_order(n)
  n.digits.sort.reverse
end

The above snippet returns following output

puts descending_order(352614)

=> [6, 5, 4, 3, 2, 1]