从Ruby中的字符串中删除最后2个字符？

I'm collecting all my user's email addresses for a mass mailing like this:

我正在收集所有用户的电子邮件地址，如下所示：

def self.all_email_addresses
  output = ''
  User.all.each{|u| output += u.email + ", " }
      output
end

However, I end up with an extra ", " on the string of email addresses.

但是，我最终在电子邮件地址字符串上添加了一个“，”。

How can I get rid of this / is there a better way to get a comma separated list of email addresses?

我怎样才能摆脱这个/有更好的方法来获得逗号分隔的电子邮件地址列表？

3 个解决方案

#1

Use join:

使用加入：

def self.all_email_addresses
  User.all.collect {|u| u.email}.join ', '
end

#2

remove the last two characters

str.chop.chop # ...or...
str[0..-3]

Although this does answer the exact question, I agree that it isn't the best way to solve the problem.

虽然这确实回答了确切的问题，但我同意这不是解决问题的最佳方法。

#3

Or just "yadayada"[0..-3] will do it.

或者只是“yadayada”[0 ..- 3]会这样做。