// our string
string myString = "test@gmail.com";
// lets remove the @ symbol
// here we replace our "@" in our string to an empty string
string newString = myString.Replace("@", string.empty);
Console.Writeline(newString);
// output should look like this: testgmail.com
// How to replace a char in string with an Empty character
string num = "1234-1234-1234-1234";
num = num.Replace("-", " ");
// result: 1234 1234 1234 1234
// How to remove a char in string
string num = "1234-1234-1234-1234";
num = num.Replace("-", string.Empty);
// result: 1234123412341234
string input; // this is your input string
string output = new string(input.Where(c => !char.IsControl(c)).ToArray());