C＃正则表达式替换问号

Question

I want to replace question mark character ? with text Rs if ? is followed by numbers.

This is what I have tried. But not working.

 string str = "DFg sdfsdaf ?145 dfgsdf ?fg";
 str = str.Replace(@"\\?", "Rs");
 Console.WriteLine(str);

Desired output:

DFg sdfsdaf Rs145 dfgsdf ?fg

Please help.

Answer 1

Try this:

Regex.Replace(str, @"\?(\d)", @"Rs$1")

It will match a literal question mark followed by a digit and replace it with Rs followed by that digit. Question marks followed by non-digits are left unchanged.

Example:

var str = "DFg sdfsdaf ?145 dfgsdf ?fg";
Console.Out.WriteLine(Regex.Replace(str, @"\?(\d)", @"Rs$1"));

Output:

DFg sdfsdaf Rs145 dfgsdf ?fg

Answer 2

Try like this too:

System.Text.RegularExpressions.Regex.Replace(str,@"\?(?=\d+)","Rs");

I would recommend this read. The above pattern looks for ? and checks if it is followed by digit one or more time then replaces ? with Rs .

Answer 3

Try this Regex

\\?((?:\d+))

Use Regex to handle this:-

  Regex oRegex = new Regex(@"\?((?:\d+))");
  str = oRegex.Replace(str, "Rs$1");