How do you remove all the alphabetic characters from a string?

Question

I have a string containg alphabetic characters, for example:

1. 254.69 meters
2. 26.56 cm
3. 23.36 inches

Answer 1

This should work:

// add directive at the top 
using System.Text.RegularExpressions;

string numberOnly = Regex.Replace(s, "[^0-9.]", "")