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

The Regex, and Vlad's LINQ answers cover the solution well. And are both good options.

I had a similar problem, but I also wanted to only explicitly strip letters, and not to strip white space or etc, with this variant.

I also wanted it usable as below. Any of the other solutions could be packaged in a similar manner.

public static string StripAlpha(this string self)
{
    return new string( self.Where(c => !Char.IsLetter(c)).ToArray() );
}

public static string StripNonNumeric(this string self)
{
    // Use Vlad's LINQ or the Regex Example
    return new string(self.Where(c=>(Char.IsDigit(c)||c=='.'||c==',')).ToArray()) ;  // See Vlad's

}

This would then be used such as:

var newString = someString.StripAlpha();
var newString2 = someString.StripNonNumeric();