ruby-on-rails - 带 ruby​​ on rails 的多维数组

Question

我必须重新排序我的目的地散列，所以我想在这样的数组中创建一个数组:

@orderedDestinations = Array.new 
@destinations.each do |destination|
  if (destination.position != nil)
    @orderedDestinations[destination.position][destination.id] = destination
  end
end

我遇到了这个错误:

You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.[]=

我做错了什么？

Answer 1

如果你想按 Destination#position 对 @destinations 进行排序，你应该这样做:

@orderedDestinations = @destinations.sort_by(&:position)

http://ruby-doc.org/core-1.9.2/Enumerable.html#method-i-sort_by

完成交易。