1. 數組的元素是Hash,請按照Hash給數組排序
- >> 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. 下面代碼運行之後結果是什麼
- class User < ActiveRecord::Base
- after_save :set_name
- private
- def set_name
- self.update_attribues(:name => 'Larry')
- end
- end
- User.create(:name => "Woe")
結果是死循環,一直save after_save.怎麼辦呢
他說了個改
before_save
然後改
self.name = "Larry"