C# 7 and .NET: Designing Modern Cross-platform Applications

Handling casting exceptions

The compiler is now happy; but, because aliceInPerson might be a different derived type, like Student instead of Employee, we need to be careful. This statement might throw an InvalidCastException error.

We can handle this by writing a try statement, but there is a better way. We can check the current type of the object using the is keyword.

Wrap the explicit cast statement in an if statement, as follows:

if (aliceInPerson is Employee) 
{ 
   WriteLine($"{nameof(aliceInPerson)} IS an Employee"); 
   Employee e2 = (Employee)aliceInPerson; 
   // do something with e2 
} 

Run the console application and view the output:

aliceInPerson IS an Employee

Alternatively, you can use the as keyword to cast. Instead of throwing an exception, ...