Interview Notes

Whats the difference betweeen Structure, Class and Enumeration ?

Structures and Enumerations are Value-Types. This means, the data that they contain is stored as a stack on the memory. Classes are Reference-Types, means they are stored as a heap on the memory.

A No-argument constructor for a structure is not possible. The structure's constructor should always have a parameter.

class A{int x = 5; //No error ...}

struct{int x = 5; //Syntax Error }

A class can inherit from one class (Multiple inheritance not possible). A Structure cannot inherit from a structure.

Whats the difference between MSIL and CIL?

MSIL is the name given to the intermediate language in .NET Framework Beta, 1.0 and 1.1. From version 2.0 onwards, the intermediate language is called CIL. We can say, MSIL is the old name. MSIL stands for Microsoft Intermediate Language. CIL stands for Common Intermediate Language.

What is the difference between Web Services and Remoting?

Both Remoting and Web Services are ways of communication between applications.

Remoting - In remoting, the applications involved in the communication process may be located on the same computer, different computers in a same or different network. In remoting, both applications know about each other. A proxy of an application object is created on the other application.

Web Services - Communication between applications using web services is platform independent and programming independent. The application that consumes the web service, simply accesses it, without needing to know how this web service has actually been implemented & created.

Here are some of the major differences:

* ASP.NET Web Services may be accessed using HTTP only. Remoting objects may be accessed over any protocol like TCP, SMTP, HTTP

* Web Service are Stateless, whereas Remoting has support for both stateless and with-state environment, which is achieved using Singleton and Singlecall activation

* ASP.NET provides good support to create Web Services. They are easy to deploy. In comparison, Remoting is little complex.

* Web services may be considered very reliable, due to the fact that they are hosted on IIS. In remoting, if IIS is'nt used, then methods like plumbing have to be used to ensure the application reliability.

* In .NET, when we create an application that consumes a web service, the web service may or may not be built using .NET. But while implementing Remoting in .NET, both the applications must be built in .NET.

* Using web services, only a limited number of types may be serialized (XML). Using Remoting, objects like SOAP objects, Binary objects & XML Objects may be serialized.

What is shared keyword used for? What is static?
Shared and Static mean the same. Shared is used in VB.NET, while Static is used in C#.