remove alpha characters and white space from string

Question

I have a string which contains many characters. I want to remove A-Za-z and white space and be left with the rest. What's the best way to do this?

Here's what I've tried

presaleEstimateHigh = Regex.Replace(presaleEstimateHigh, @"[A-Za-z]", string.Empty);

but I also need to remove white space.

Answer 1

You can use \s.

For example:

presaleEstimateHigh = Regex.Replace(presaleEstimateHigh, @"[A-Za-z\s]", string.Empty);

Answer 2

Without regular expressions:

var chars = str.Where(c => !char.IsLetter(c) && !char.IsWhitespace(c)).ToArray();
var rest = new string(chars);