Find and replace numbers in string with regex

Question

What I'm trying to achieve is to replace the numbers in the string with a new values calculated from the (match * int).

So the string input looks like:

500g Flour
14g Salt
7g Dry yeast
45ml Olive oil
309ml Water

And the result should look like this:

1000g Flour
28g Salt
14g Dry yeast
90ml Olive oil
618 ml Water

row["ingredients"] is a DataRow.

This is where I'm at:

System.Text.RegularExpressions.
        Regex.Replace(row["ingredients"].ToString(), 
                      @"[^/d]", Delegate(Match match) { return match * 2; },
                      RegexOptions.Multiline);

Any solution is greatly appreciated.

Answer 1

The first problem is that your regex is only matching characters that are not a digit.

Correction: It is using forward slashes instead of a backslash, so it's matching anything that is not a slash or a d

Change your regex to @"\b(\d+)"

Here's a working example on dotnetfiddle.net

using System;
using System.Text.RegularExpressions;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            var string1 = "500g Flour 14g Salt 7g Dry yeast 45ml Olive oil 309ml Water";

            var result = Regex.Replace(string1, @"\b(\d+)", Doubler, RegexOptions.Multiline);

            Console.WriteLine(result);

            Console.ReadKey();
        }

        private static string Doubler(Match match)
        {
            return (Convert.ToInt32(match.Value)*2).ToString();
        }
    }
}

Answer 2

[^/d] means "any character except slash or the letter d".

To match a number, use \d+.