Reverse capture groups with gsub and a block (Ruby)

Question

Is it possible to do something like this (without modifying this code):

a = '1 and 2'
b = a.gsub(/(\d)/) do |match|
  # Print 2 and 1, reversing the captures matches
end

I know I can do a.gsub((\\d) and (\\d)) and then refer to the matched groups in the block as #$1 and #$2 but I was wondering if it's possible to capture both 1 and 2 in the block without doing this.

Answer 1

更短的非gsub解决方案：

a.split(" ").reverse.join(' ')

Answer 2

It is impossible or difficult to do it exactly in that format, but here is something close:

"1 and 2".scan(/\d/).reverse.join(" and ")
# => "2 and 1"

Answer 3

如果您愿意，可以使用非gsub代码：

a.split(/[^\d]/).select{|s|!s.empty?}.reverse

Answer 4

I would do as below :

a = '1 and 2'
a.split(" ").reverse.join(" ")
# => "2 and 1"