正则表达式替换特定匹配项的字符串的第一个和最后一个字符

Question

Something like this.

The sentence is

string ttt = "This is ?chef? and ?teacher? time";

This sentence should change to

ttt = "This is 'chef' and 'teacher' time";

I was looking at some online samples Regex.Replace(ttt, @"\\?([^\\$]*)\\?", "REPLACE"); but I am not able to figure out what should I write in place of REPLACE . It should be per word basis.

Kindly help me with this.

Answer 1

You would reference the capture group inside the replacement call. It's called a back-reference.

String ttt = "This is ?chef? and ?teacher? time";
String result = Regex.Replace(ttt, @"\?([^?]*)\?", "'$1'");
Console.WriteLine(result); //=> "This is 'chef' and 'teacher' time"

Back-references recall what was matched by a capture group ( ... ) . A backreference is specified as ( $ ); followed by a digit indicating the number of the group to be recalled.

Note: I used [^?] for the negation instead of matching everything except a literal $ here.

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But if you're just wanting to replace ? , a simple replacement would suffice:

String result = ttt.Replace("?", "'");