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

Using LINQ:

using System.Linq;

string input ="57.20000 KG ";
string output = new string(input.Where(c=>(Char.IsDigit(c)||c=='.'||c==',')).ToArray());