ruby-on-rails - ruby 注入(inject)方法没有做我认为应该做的事情

Question

有谁知道为什么会失败？

ree-1.8.7-2011.03 :008 > 3.times.inject({}) {|result, el| result[el.months.ago.strftime("%B")] = "blah"}
IndexError: string not matched
  from (irb):8:in `[]='
  from (irb):8
  from (irb):8:in `inject'
  from (irb):8:in `each'
  from (irb):8:in `times'
  from (irb):8:in `each'
  from (irb):8:in `

Answer 1

inject将 block 的返回值作为 result 提供给下一次迭代，但 Hash 分配返回分配的内容。从 block 中返回 result:

3.times.inject({}) {|result, el| result[el.months.ago.strftime("%B")] = "blah"; result }

或使用 each_with_object因为你并没有真正注入(inject):

3.times.each_with_object({}) {|el, result| result[el.months.ago.strftime("%B")] = "blah" }