how to see if string has only letters c# code example

Example 1: c# check if string is only letters and numbers

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

Example 2: how to check that string has only alphabet in c#

Regex.IsMatch(input, @"^[a-zA-Z0-9]+$");