ruby-blank?
>|ruby|
hoge = nil
hoge.nil? => true
hoge.empty? => ERROR
hoge.blank? => true
||<
>|ruby|
hoge = ''
hoge.nil? => false
hoge.empty? => true
hoge.blank? => true
||<
>|ruby|
hoge = 0
hoge.nil? => false
hoge.empty? => ERROR
hoge.blank? => false
||<
なるほど。。。