Ruby replace string with captured regex pattern

Question

I am having trouble translating this into Ruby.

Here is a piece of JavaScript that does exactly what I want to do:

function get_code(str){
    return str         


        

Answer 1

\1 in double quotes needs to be escaped. So you want either

"Z_sdsd: sdsd".gsub(/^(Z_.*): .*/, "\\1")

or

"Z_sdsd: sdsd".gsub(/^(Z_.*): .*/, '\1')

see the docs on gsub where it says "If it is a double-quoted string, both back-references must be preceded by an additional backslash."

That being said, if you just want the result of the match you can do:

"Z_sdsd: sdsd".scan(/^Z_.*(?=:)/)

or

"Z_sdsd: sdsd"[/^Z_.*(?=:)/]

Note that the (?=:) is a non-capturing group so that the : doesn't show up in your match.