To illustrate the use of a throw expression, create a method called GetNameLength() in the Chapter1 class. All it does is check to see if the length of a name is not zero. If it is, then the method will throw an exception right there in the expression.
public int GetNameLength(string firstName, string lastName) { return (firstName.Length + lastName.Length) > 0 ? firstName.Length + lastName.Length : throw new Exception("First name and last name is empty"); }
To see the throw expression in action, create an instance of the Chapter1 class and call the GetNameLength() method. Pass it two blank strings as parameters.
try { Chapter1 ch1 = new Chapter1(); int nameLength = ch1.GetNameLength("", ""); } catch (Exception ex) { WriteLine(ex.Message); }
Running your console application will then return the exception message as the output.