同时更换2个字符串？

how can I replace 2 strings in the same time? for example let's say I have string like this:

如何在同一时间更换2个字符串?例如,假设我有这样的字符串:

str1 = "AAAA BBBB CCCC DDDD"

str1 =“AAAA BBBB CCCC DDDD”

i want to replace every "AAAA" with "CCCC" and every "CCCC" with "AAAA" but if i did:

我想用“CCCC”替换每个“AAAA”,用“AAAA”替换每个“CCCC”,但如果我这样做:

str1.gsub("AAAA","CCCC") # CCCC BBBB CCCC DDDD

str1.gsub(“AAAA”,“CCCC”)#CCCC BBBB CCCC DDDD

str1.gsub("CCCC","AAAA") # AAAA BBBB AAAA DDDD

str1.gsub(“CCCC”,“AAAA”)#AAAA BBBB AAAA DDDD

what I want str1 to be "CCCC BBBB AAAA DDDD"

我希望str1成为“CCCC BBBB AAAA DDDD”

3 个解决方案

#1

General answer:
Use a regex to match both AAAA and CCCC, then substitute each match with CCCC and AAAA respectively.

一般答案:使用正则表达式匹配AAAA和CCCC,然后分别用CCCC和AAAA替换每个匹配。

edit to clear up the confusion

编辑以消除混乱

str1.gsub(/(AAAA|CCCC)/) { $1 == 'AAAA' ? 'CCCC' : 'AAAA' }

edit i thought of a more elegant way too :)

编辑我想到了更优雅的方式:)

str1.gsub(/((AAAA)|(CCCC))/) { $2 ? 'CCCC' : 'AAAA' }

#2

Is it an option for you to replace AAAA with something else first and then proceed?

您可以选择先用其他东西替换AAAA,然后继续吗?

str1.gsub("AAAA","WXYZ") # WXYZ BBBB CCCC DDDD
str1.gsub("CCCC","AAAA") # WXYZ BBBB AAAA DDDD
str1.gsub("WXYZ","CCCC") # CCCC BBBB AAAA DDDD

#3

A solution (although something based around regex would be best) would be something along the lines of creating a replacement hash as such, which can be extended as needed. I just quickly put this together to demonstrate. I'm sure with a bit more love and care you can come up with something more elegant that works along the same lines as this implementation only works for strings with spaces.

一个解决方案(虽然基于正则表达式的东西是最好的)将像创建替换哈希一样,可以根据需要进行扩展。我只是快速将它们放在一起展示。我肯定会有更多的爱和关心,你可以想出一些更优雅的东西,它们的工作方式相同,因为这个实现只适用于带空格的字符串。

str1 = "AAAA BBBB CCCC DDDD"    
replacements = { "AAAA" => "CCCC", "CCCC" => "AAAA", "XXXX" => "ZZZZ" } # etc...

new_string = ""
str1.split(" ").each do |s| 
    new_string += replacements[s] || s
    new_string += " "
end

puts new_string # CCCC BBBB AAAA DDDD

#1