使用IRB,为什么日期和;时间类自动加载,但DateTime不是吗?我必须require 'date'
,这对我来说没有意义,因为我认为Date和DateTime都在使用标准库'date'
?
ruby-1.9.2-p290 :001 > Date
=> Date
ruby-1.9.2-p290 :002 > Time
=> Time
ruby-1.9.2-p290 :003 > DateTime
NameError: uninitialized constant Object::DateTime
from (irb):3
from /Users/kamilski81/.rvm/rubies/ruby-1.9.2-p290/bin/irb:16:in `<main>'
ruby-1.9.2-p290 :004 > require 'date'
=> true
ruby-1.9.2-p290 :005 > require 'date'
=> false
ruby-1.9.2-p290 :006 > DateTime
=> DateTime