c# regex only letters code example

Example 1: c# regex number only

Regex

string input = "1-205-330-2342";
string result = Regex.Replace(input, @"[^\d]", "");  //number only

Example 2: c# check if string is only letters and numbers

if (textVar.All(c => Char.IsLetterOrDigit(c))) {
    // String contains only letters & numbers
}

Example 3: regex only letters and numbers c#

Actually I found the issue, I was validating the string during the TextBox object's creation, instead of when it updates so there was no way for that code to be executed when it was needed. My bad