Ruby 或正则表达式去除多余的换行符

Question

你会如何改变这个:

Dear FredHow are you?RegardsJohn

进入这个:

Dear FredHow are you?RegardsJohn

注意:单断和双断是允许的，但不能超过。例如，我们想从:

"Dear Fred\n\n\n\nHow are you?\n\n\n\n\n\n\nRegards\nJohn"

到

"Dear Fred\n\nHow are you?\n\nRegards\nJohn"

但也适用于“\r\n”。

Answer 1

是这样的吗？

s.gsub /(\r?\n){3,}/, '\1\1'

似乎至少适用于您的示例:

irb(main):060:0> s
=> "Dear Fred\n\n\n\nHow are you?\n\n\n\n\n\n\nRegards\nJohn"
irb(main):061:0> s.gsub /(\r?\n){3,}/, '\1\1'
=> "Dear Fred\n\nHow are you?\n\nRegards\nJohn"