How to get the count of only special character in a string using Regex?

Question

If my input string is ~!@#$%^&*()_+{}:\"<>?

How do I get the count of each special character using Regex? For example:

Regex.Match         


        

Answer 1

Instead of thinking of every special characters and adding them up, do it the other way; count every letters/digits and subtract them from the count.

You can do that with a simple one-liner :

string input = "abc?&;3";
int numberOfSpecialCharacters = input.Length - input.Count(char.IsLetterOrDigit); //Gives 3

Which you can also change to

int numberOfSpecialCharacters = input.Count(c => !char.IsLetterOrDigit(c));