sorting a ruby array of objects by an attribute that could be nil

Question

I have an array of objects that I need to sort by a position attribute that could be an integer or nil, and I need the objects that have the nil position to be at the end of

Answer 1

I haven't done Ruby in a while, but you could split the null-checking from the sorting (and just allow Child#position to return null):

def sorted_children
  children.reject{|c| c.position.nil?}.sort_by(&:position) +
    children.select{|c| c.position.nil?}
end

Admittedly it's not the most efficient solution, but it doesn't have any magic numbers.