ASP.NET Interview Questions and Answers Set 3

21.What is enum in C#?

enum keyword is used for declaring an enumeration, which consists of named constants and it is called as enumerator lists. Enums are value types in C# and these can’t be inherited. Below is the sample code of using Enums

Eg: enum Fruits { Apple, Orange, Banana, WaterMelon};

22. Write a sample code to write the contents to text file in C#?

Below is the sample code to write the contents to text file –

Using System.IO;

File.WriteAllText(”mytextfilePath”, “MyTestContent”);

23. Explain Anonymous type in C#?

This is being added in C# 3.0 version. This feature enables us to create an object at compile time. Below is the sample code for the same –

Var myTestCategory = new { CategoryId = 1, CategoryName = “Category1”};

24.Which string method is used for concatenation of two strings in c#?

“Concat” method of String class is used to concatenate two strings. For example,

string.Concat(firstStr, secStr)

25.What is overriding in c# ?

To override a base class method which is defined as virtual, Override keyword is used. In the above example, method DriveType is overridden in the derived class.

26.What is ASP.Net?

It is a framework developed by Microsoft on which we can develop new generation web sites using web forms(aspx), MVC, HTML, Javascript, CSS etc. Its successor of Microsoft Active Server Pages(ASP). Currently there is ASP.NET 4.0, which is used to develop web sites. There are various page extensions provided by Microsoft that are being used for web site development.

Eg: aspx, asmx, ascx, ashx, cs, vb, html, XML etc.

27.What’s the use of Response.Output.Write()?

We can write formatted output using Response.Output.Write().

28.What is caching?

Caching is a technique used to increase performance by keeping frequently accessed data or files in memory. The request for a cached file/data will be accessed from cache instead of actual location of that file.

29.What is Cross Page Posting?

When we click submit button on a web page, the page post the data to the same page. The technique in which we post the data to different pages is called Cross Page posting. This can be achieved by setting POSTBACKURL property of the button that causes the postback. Findcontrol method of PreviousPage can be used to get the posted values on the page to which the page has been posted.

30.What is RedirectPermanent in ASP.Net?

RedirectPermanent Performs a permanent redirection from the requested URL to the specified URL. Once the redirection is done, it also returns 301 Moved Permanently responses.