Some good tips

http://errtheblog.com/posts/42-rails-rubyisms-advent
<br />>> { 'days' => 25, 'spirit' => 'giving', 'wallet' => 'empty' }.symbolize_keys<br />=> {:wallet=>"empty", :spirit=>"giving", :days=>25}<br />>> { 'system' => 'wii', :valid_ages => 5..90 }.stringify_keys<br />=> {"valid_ages"=>5..90, "system"=>"wii"}<br /><br />>> colors = { :foreground => 'red', :background => 'black' } <br />=> {:background=>"black", :foreground=>"red"}<br />>> colors.merge(:background => 'green')<br />=> {:background=>"green", :foreground=>"red"}<br /><br /># doesn't override our set colors but would add in :background<br /># if we didn't already have it:<br />>> colors.reverse_merge(:background => 'green')<br />=> {:background=>"black", :foreground=>"red"}<br /><br />>> name = { :first => 'Chris', :last => 'Wanstrath', :middle => 'Jebediah' }<br />=> {:first=>"Chris", :last=>"Wanstrath", :middle=>"Jebediah"}<br />>> name.diff(:first => 'Chris', :last => 'Wanstrath', :middle => 'Jonesy')<br />=> {:middle=>"Jebediah"}<br />>> name.diff(:first => 'Chris', :last => 'Wanstrath')<br />=> {:middle=>"Jebediah"} <br />
<br />>> Hash.from_xml '<posts><post><id>1</id></post></posts>'<br />=> {"posts"=>{"post"=>{"id"=>"1"}}} <br />>> Hash.from_xml '<posts><post><id>1</id></post><post><id>2</id></post></posts>'<br />=> {"posts"=>{"post"=>[{"id"=>"1"}, {"id"=>"2"}]}}<br />
<br /><br />>> 2.even?<br />=> true<br />>> 2.odd?<br />=> false<br />>> 99.multiple_of? 60<br />=> false<br />>> 25.multiple_of? 5<br />=> true<br />
<br /> magical_people = [ { :name => "Santa Claus", :color => "Red" }, <br /> { :name => "Mrs Claus", :color => "Red" }, <br /> { :name => "Twinkle the Elf", :color => "Green "} ]<br />=> [{:name=>"Santa Claus", :color=>"Red"}, {:name=>"Mrs Claus", :color=>"Red"}, {:name=>"Twinkle the Elf", :color=>"green "}]<br />>> magical_people.group_by { |person| person[:color] }<br />=> {"Green "=>[{:name=>"Twinkle the Elf", :color=>"green "}],<br /> "Red"=>[{:name=>"Santa Claus", :color=>"Red"}, {:name=>"Mrs Claus", :color=>"Red"}]} <br />
<br />>> beatles = [{ :first => 'John', :last => 'Lennon' }, <br /> { :first => 'Paul', :last => 'McCartney' }, <br /> { :first => 'Evan', :last => 'Weaver' }, <br /> { :first => 'Ringo', :last => 'Starr' }]<br />=> [{:first=>"John", :last=>"Lennon"}, {:first=>"Paul", :last=>"McCartney"}, {:first=>"Evan", :last=>"Weaver"}, {:first=>"Ringo", :last=>"Starr"}]<br />>> beatles.index_by { |beatle| beatle[:first] }<br />=> {"Evan"=>{:first=>"Evan", :last=>"Weaver"}, <br /> "Paul"=>{:first=>"Paul", :last=>"McCartney"}, <br /> "John"=>{:first=>"John", :last=>"Lennon"}, <br /> "Ringo"=>{:first=>"Ringo", :last=>"Starr"}}<br />
<br />>> [1,2,3,4,5].sum<br />=> 15<br />>> Recipe.find(:all).sum { |recipe| recipe.total_time.to_i }<br />=> 1777<br />
<br />class User < ActiveRecord::Base<br /> alias_attribute :user_id, :id<br />end<br /><br />>> user = User.find(:first)<br />=> #<User:0x12622fc ... ><br />>> user.id<br />=> 1<br />>> user.user_id<br />=> 1<br />>> user.user_id?<br />=> true<br />
<br />>> (7.days.ago..1.day.ago).to_s(:db)<br />=> "BETWEEN '2006-12-11 02:06:50' AND '2006-12-17 02:06:50'" <br />