.NET Developer Interview Answers

  1. What does an application server do?
    An application server is a software engine that delivers applications to client computers or devices. The application server runs your server code. Some well known application servers are IIS (Microsoft), WebLogic Server (BEA), JBoss (Red Hat), WebSphere (IBM).
  2. What is a base class and derived class?
    The class is the template for creating objects. A base class derives fundamental functionality from other classes whereas a derived class derives its functionality from a base class.
  3. What’s the difference between interface and an abstract class?
    An abstract class is a class that cannot be instantiated, but must be inherited from.  An interface, by contrast, is a totally abstract set of members that can be thought of as defining a contract for conduct. The implementation of an interface is left completely to the developer.
  4. The difference between an inner join and a full join?
    An inner join gets all records from one table that have some related entry in a second table. A full join will get all its records from both left and right tables.
  5. Is string a value type or a reference type?
    A string is a reference type. Value types need a known size for the stack which a string can’t do. As a reference type, the size of the reference is known in advance, even if the string isn’t.
  6. Can you tell me what strong typing is versus weak typing?
    Strong-typing means that you can't use one type of variable where another is expected (or have restrictions to doing so). Weak-typing means you can mix different types. In PHP for example, you can mix numbers and strings and PHP won't complain because it is a weakly-typed language.
  7. What is boxing/unboxing?
    Boxing is used to convert value types to object.
    E.g. int x = 1;
    object obj = x ;
    Unboxing is used to convert the object back to the value type.
    E.g. int y = (int)obj;
    Boxing/unboxing is quiet an expensive operation.
  8. What is the Global Assembly Cache do and what problem does it solve?
    GAC is a machine-wide cache of assemblies that allows .NET applications to share libraries. GAC solves some of the problems associated with DLLs.
  9. What are events and delegates?
    An event is a message sent by a control to notify the occurrence of an action. However it is not known which object receives the event. For this reason, .NET provides a special type called Delegate which acts as an intermediary between the sender object and receiver object.
  10. What is object role modeling (ORM) ?
    It is a logical model for designing and querying database models. There are various ORM tools in the market like CaseTalk, Microsoft Visio for Enterprise Architects, Infagon etc.
  11. What is the difference between localization and globalization?
    Localization is the process of customizing applications that support a given culture and regions. Globalization is the process of customizing applications that support multiple cultures and regions.