C# Interview Question

Question

1.When should you use Abstract class over interface and interface over abstract class?

 

2.What is different between ArrayList and List?

 

3.What is reflection in c#?

 

4.What is different between Debug and Release mode in Visual studio?

 

5. What would be output? Is this program run or generate compile time error?If run then why? if nor then why?

Note : Here i am using private access modifier with main() function.

      private static void Main()

      {

         Console.WriteLine("Hello C#!!");

       }