ruby-on-rails - ruby rails : short hand to put commas in between elements in an array?

Question

users_allowed_to_be_viewed.map {|u| "#{u.id},"}

但这给出了 1,2,3,

什么是获得类似 1,2,3

的捷径

Answer 1

数组？

来自 http://ruby-doc.org/core/classes/Array.html

 array.join(sep=$,) → str

Returns a string created by converting each element of the array to a string, separated by sep.

       [ "a", "b", "c" ].join        #=> "abc"
       [ "a", "b", "c" ].join("-")   #=> "a-b-c"