You have a class named Customer and a variable named customers.
You need to test whether the customers’ variable is a generic list of Customer objects.
Which line of code should you use?
A.
Option A
B.
Option B
C.
Option C
D.
Option D
Explanation:
If you want to check if it’s an instance of a generic type:
return list.GetType().IsGenericType;
If you want to check if it’s a generic List<T>:return list.GetType().GetGenericTypeDefinition() == typeof(List<>);
Testing if object is of generic type in C#
http://stackoverflow.com/questions/982487/testing-if-object-is-of-generic-type-in-c-sharp
A
26
0
Agree, A.
5
0
A
3
0
A
0
0
The answer is A
Tested in VS.
public class Question7
{
public void TestCustomerObject()
{
Customer cust = new Customer();
List custList = new List();
custList.Add(cust);
if(custList.GetType() is List)
{
Console.WriteLine(“True”);
}
else
{
Console.WriteLine(“False”);
}
}
public class Customer
{
public string name { get; set; }
}
}
4
2
namespace ConsoleApplication
{
class Program
{
static void Main(string[] args)
{
var customers = new List();
Console.WriteLine(“customers is List : ”
+ (customers is List));
Console.WriteLine(“customers is List[] : ”
+ (customers is List[]));
Console.WriteLine(“customers.GetType() is List[] : ”
+ (customers.GetType() is List[]));
Console.WriteLine(“customers.GetType() is List : ”
+ (customers.GetType() is List));
Console.ReadLine();
}
}
class Customer
{
}
}
// Display
customers is List : True
customers is List[] : False
customers.GetType() is List[] : False
customers.GetType() is List : False
8
0
It’s A
1
0