ruby的一些面试题

1. 数组的元素是Hash，请按照Hash给数组排序

>> arr << {:name => 3, :type1 => 'b'}
=> [{:type1=>"a", :name=>1}, {:type1=>"c", :name=>2}, {:type1=>"b", :name=>3}]
>> arr.sort_by{|x| x[:type1]}
=> [{:type1=>"a", :name=>1}, {:type1=>"b", :name=>3}, {:type1=>"c", :name=>2}]
>> arr.sort{|x, y| x[:type1] <=> y[:type1]}
=> [{:type1=>"a", :name=>1}, {:type1=>"b", :name=>3}, {:type1=>"c", :name=>2}]

2. 下面代码运行之后结果是什么

class User < ActiveRecord::Base
  after_save :set_name
  private
  def set_name
    self.update_attribues(:name => 'Larry')
  end
end

User.create(:name => "Woe")

结果是死循环，一直save after_save.怎么办呢 
他说了个改 
before_save 
然后改 
self.name = "Larry"