Question

有没有更好的方法来声明这个？

if current_user.received_replies.unread.count > 0

我想要做的只是在至少有一个unread对象的情况下匹配条件。

Answer 1

unless current_user.received_replies.unread.empty?
  # ...
end

或者，如果您的if有一个else，请切换案例（因为unless/else很难得）：

if current_user.received_replies.unread.empty?
  # ...
else
  # ...
end

Answer 2

我会用：

if current_user.received_replies.unread.any?

来自文档：

= Array.any?

(from ruby core)
=== Implementation from Enumerable
------------------------------------------------------------------------------
  enum.any? [{|obj| block } ]   -> true or false

------------------------------------------------------------------------------

Passes each element of the collection to the given block. The method returns
true if the block ever returns a value other than false or nil. If the block
is not given, Ruby adds an implicit block of {|obj| obj} (that is any? will
return true if at least one of the collection members is not false or nil.

       %w{ant bear cat}.any? {|word| word.length >= 3}   #=> true
       %w{ant bear cat}.any? {|word| word.length >= 4}   #=> true
       [ nil, true, 99 ].any?                            #=> true

Answer 3

这可能会更好一点：

unless current_user.received_replies.unread.empty?

评估数组是否包含ruby中的任何项目

3 个答案: