Interview Question (8920128728): 2020

Monday, December 28, 2020

Hadoop Questions and Answers – Compression

This set of Hadoop Multiple Choice Questions & Answers (MCQs) focuses on “Compression”.

1. The _________ codec from Google provides modest compression ratios.
a) Snapcheck
b) Snappy
c) FileCompress
d) None of the mentioned

Answer: b
Explanation: Snappy has fast compression and decompression speeds.

2. Point out the correct statement.
a) Snappy is licensed under the GNU Public License (GPL)
b) BgCIK needs to create an index when it compresses a file
c) The Snappy codec is integrated into Hadoop Common, a set of common utilities that supports other Hadoop subprojects
d) None of the mentioned

Answer: c
Explanation: You can use Snappy as an add-on for more recent versions of Hadoop that do not yet provide Snappy codec support.

3. Which of the following compression is similar to Snappy compression?
a) LZO
b) Bzip2
c) Gzip
d) All of the mentioned

Answer: a
Explanation: LZO is only really desirable if you need to compress text files.

4. Which of the following supports splittable compression?
a) LZO
b) Bzip2
c) Gzip
d) All of the mentioned

Answer: a
Explanation: LZO enables the parallel processing of compressed text file splits by your MapReduce jobs.

5. Point out the wrong statement.
a) From a usability standpoint, LZO and Gzip are similar
b) Bzip2 generates a better compression ratio than does Gzip, but it’s much slower
c) Gzip is a compression utility that was adopted by the GNU project
d) None of the mentioned

Answer: a
Explanation: From a usability standpoint, Bzip2 and Gzip are similar.

6. Which of the following is the slowest compression technique?
a) LZO
b) Bzip2
c) Gzip
d) All of the mentioned

Answer: b
Explanation: Of all the available compression codecs in Hadoop, Bzip2 is by far the slowest.

7. Gzip (short for GNU zip) generates compressed files that have a _________ extension.
a) .gzip
b) .gz
c) .gzp
d) .g

Answer: b
Explanation: You can use the gunzip command to decompress files that were created by a number of compression utilities, including Gzip.

8. Which of the following is based on the DEFLATE algorithm?
a) LZO
b) Bzip2
c) Gzip
d) All of the mentioned

Answer: c
Explanation: gzip is based on the DEFLATE algorithm, which is a combination of LZ77 and Huffman Coding.

9. __________ typically compresses files to within 10% to 15% of the best available techniques.
a) LZO
b) Bzip2
c) Gzip
d) All of the mentioned

Answer: b
Explanation: bzip2 is a freely available, patent free (see below), high-quality data compressor.

10. The LZO compression format is composed of approximately __________ blocks of compressed data.
a) 128k
b) 256k
c) 24k
d) 36k

Answer: b
Explanation: LZO was designed with speed in mind: it decompresses about twice as fast as gzip, meaning it’s fast enough to keep up with hard drive read speeds.

Hadoop Questions and Answers – Hadoop I/O

This set of Hadoop Multiple Choice Questions & Answers (MCQs) focuses on “Hadoop I/O”.

1. Hadoop I/O Hadoop comes with a set of ________ for data I/O.
a) methods
b) commands
c) classes
d) none of the mentioned

Answer: d
Explanation: Hadoop I/O consist of primitives for serialization and deserialization.

2. Point out the correct statement.
a) The sequence file also can contain a “secondary” key-value list that can be used as file Metadata
b) SequenceFile formats share a header that contains some information which allows the reader to recognize is format
c) There’re Key and Value Class Name’s that allow the reader to instantiate those classes, via reflection, for reading
d) All of the mentioned

Answer: d
Explanation: In contrast with other persistent key-value data structures like B-Trees, you can’t seek to specified key editing, adding or removing it.

3. Apache Hadoop ___________ provides a persistent data structure for binary key-value pairs.
a) GetFile
b) SequenceFile
c) Putfile
d) All of the mentioned

Answer: b
Explanation: SequenceFile is append-only.

4. How many formats of SequenceFile are present in Hadoop I/O?
a) 2
b) 3
c) 4
d) 5

Answer: b
Explanation: SequenceFile has 3 available formats: An “Uncompressed” format, a “Record Compressed” format and a “Block-Compressed”.

5. Point out the wrong statement.
a) The data file contains all the key, value records but key N + 1 must be greater than or equal to the key N
b) Sequence file is a kind of hadoop file based data structure
c) Map file type is splittable as it contains a sync point after several records
d) None of the mentioned

Answer: c
Explanation: Map file is again a kind of hadoop file based data structure and it differs from a sequence file in a matter of the order.

6. Which of the following format is more compression-aggressive?
a) Partition Compressed
b) Record Compressed
c) Block-Compressed
d) Uncompressed

Answer: c
Explanation: SequenceFile key-value list can be just a Text/Text pair, and is written to the file during the initialization that happens in the SequenceFile.

7. The __________ is a directory that contains two SequenceFile.
a) ReduceFile
b) MapperFile
c) MapFile
d) None of the mentioned

Answer: c
Explanation: Sequence files are data file (“/data”) and the index file (“/index”).

8. The ______ file is populated with the key and a LongWritable that contains the starting byte position of the record.
a) Array
b) Index
c) Immutable
d) All of the mentioned

Answer: b
Explanation: Index doesn’t contains all the keys but just a fraction of the keys.

9. The _________ as just the value field append(value) and the key is a LongWritable that contains the record number, count + 1.
a) SetFile
b) ArrayFile
c) BloomMapFile
d) None of the mentioned

Answer: b
Explanation: The SetFile instead of append(key, value) as just the key field append(key) and the value is always the NullWritable instance.

10. ____________ data file takes is based on avro serialization framework which was primarily created for hadoop.
a) Oozie
b) Avro
c) cTakes
d) Lucene

Answer: b
Explanation: Avro is a splittable data format with a metadata section at the beginning and then a sequence of avro serialized objects.

Using a View from SQL Server in C# & Asp.net

You could use something like the following. But it's usually considered evil to put hardcoded SQL commands into .Net code. It's much better and safer to use stored procedures instead.

This should get you started. You can modify it to use stored procedures by

changing the command.CommandType to indicate it's a stored proc call
And adding the proper parameters to the command that your SP needs.
Change command.CommandText to the name of your SP, thus eliminating the hardcoded SQL.

sample code below:

using (SqlConnection connection = new SqlConnection("Data Source=raven\\sqlexpress;Initial Catalog=ucs;Integrated Security=True;Pooling=False"))
{
    using (SqlCommand command = connection.CreateCommand())
    {
        command.CommandText = "SELECT * from your_view WHERE your_where_clause";

        connection.Open();
        using (SqlDataReader reader = command.ExecuteReader())
        {
            while (reader.Read())
            {
                // process result
                reader.GetInt32(0); // get first column from view, assume it's a 32-bit int
                reader.GetString(1); // get second column from view, assume it's a string
                // etc.
            }
        }
    }
}

Multiple Choice Questions - Angular2 Directives

1. In Angular 2 . . . . . . . . directive allows us to iterate through a collection.

A) NgRepeat
B) NgWhile
C) NgIf
D) NgFor

2. Both the following examples involving the directives are identical:

A) True
B) False

3. The shadow DOM allows to encapsulate the styles of web components without allowing them to leak outside the component’s scope. If we want Angular’s renderer to use the shadow DOM, we can use . . . . . . .

A) ViewEncapsulation.None
B) ViewEncapsulation.Native
C) ViewEncapsulation.Emulated
D) ViewEncapsulation.Natural

4. Which of the below syntax will clone and inject pieces of templated HTML snippets in the markup, removing it from the DOM when the condition evaluates to false.

A) *ngIf="conditional"
B) [hidden]="conditional"
C) ngIf*="conditional"
D) None of above

5. The three types of directives in Angular 2 are . . . . . . . . . . .

A) advanced directives
B) attribute directives
C) structural directives
D) components

6. We can use the NgFor and NgIf directives using the . . . . . . . symbol to indicate we're dealing with a directive that creates a template.

A) hash (#)
B) escape (/)
C) asterisk (*)
D) percent (%)

7. A special mention is required about the children element marked with the . . . . . . . . . . . directive attribute. This attribute qualifies the template that will be displayed when no other value defined by its ngSwitchWhen siblings matches the parent conditional expression.

A) ngDefault
B) ngTemplateDefault
C) ngDefaultSwitch
D) ngSwitchDefault

8. Since Angular 2 defines a set of built-in directives, the . . . . . . . . method passes them in a similar way in order to make them available in the entire application in order to prevent us from code duplications.

A) startup
B) bootstrap
C) constructor
D) initialization

9. Structural directives change the DOM layout by adding and removing DOM elements and the . . . . . . . . directives change the appearance or behavior of an element.

A) attribute
B) advanced
C) component
D) same

10. . . . . . . . . . refers to values that parameterize the directive’s behaviour and/or view. On the other hand, . . . . . . . . refers to events that the directive fires when something special happens.

A) Inputs, output
B) Output, inputs

Answers

1) d, 2) a, 3) b, 4) a, 5) b,c,d, 6) c, 7) d, 8) b, 9) a, 10) a

Sunday, December 27, 2020

Automatically Click Mouse in every 2 minutes

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Configuration;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Media;

using System.Runtime.InteropServices;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

namespace MouseMoverTest

{

public partial class Form1 : Form

{

Timer tmr = new Timer();

[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

public static extern void mouse_event(uint dwFlags, uint dx, uint dy, uint cButtons, uint dwExtraInfo);

//Mouse actions

private const int MOUSEEVENTF_LEFTDOWN = 0x02;

private const int MOUSEEVENTF_LEFTUP = 0x04;

static int serviceWaitTime = Convert.ToInt32(ConfigurationManager.AppSettings["TimeToClick"]);

public Form1()

{

InitializeComponent();

}

private void Form1_Load(object sender, EventArgs e)

{

tmr.Tick += new System.EventHandler(tmr_Tick);

tmr.Interval = serviceWaitTime;

tmr.Enabled = true;

}

private void tmr_Tick(object sender, EventArgs e)

{

tmr.Enabled = false;

DoMouseClick();

tmr.Enabled = true;

}

public void DoMouseClick()

{

//Call the imported function with the cursor's current position

uint X = (uint)Cursor.Position.X;

uint Y = (uint)Cursor.Position.Y;

mouse_event(MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP, X, Y, 0, 0);

SoundPlayer simpleSound = new SoundPlayer(@"c:\Windows\Media\chimes.wav");

simpleSound.Play();

}

ASP.Net MVC Interview Questions and Answers List

1. Which is the best approach to assign a session in MVC?

A) System.Web.HttpContext.Current.Session[“LoginID”] =7;
B) Current.Session[“LoginID”] =7;
C) Session[“LoginID”] =7;
D) None
Ans: B

2. RedirectToActionPermanent() Method for which Status code represents?
A) 304
B) 302
C) 301
D) 300
E) None
Ans: C

3. RedirectToAction() Method for which Status code represents?
A) 304
B) 302
C) 301
D) 300
E) None
Ans: B

4. What is ActionResult() ?
A) It is an abstract Class
B) It is a Concrete Class
C) Both A and B
D) None
Ans: A

5. What is ViewResult() ?
A) It is an abstract Class
B) It is a Concrete Class
C) Both A and B
D) None
Ans: b

6. return View() works like in ASP.Net MVC C# as
A) Server.Transfer()
B) Response.Redirect()
C) Both A and B
D) None
Ans: A

7. RedirectToAction() works like in ASP.Net MVC C# as
A) Server.Transfer()
B) Response.Redirect()
C) Both A and B
D) None
Ans: B

8. In which format data can be return from XML into table ?
A) DataSet
B) Datatable
C) A and B
D) None
Ans: A

9. Can we use view state in MVC ?
A) Yes
B) No
C) Both A & B
D) None
Ans: B

10. What Request Processing technique follows ASP.Net ?
A) Top-Down
B) Down-Up
C) Pipeline
D) Water fall
Ans: C

11. What is DRY principle in ASP.Net ?
A) Don’t repeat yourself.
B) Don’t revise yourself.
C) both a and b
D) None
Ans: A

12. What is default authentication in Internet Information Services (IIS)?
A) Standard User
B) Administrator
C) Anonymous
D) None
Ans: C

13. What is the extension of MVC view when using C#?
A) cshtml
B) vbhtml
C) None
D) Both A & B
Ans: A

14. What is the extension of MVC view when using vb.net?
A) cshtml
B) vbhtml
C) None
D) Both A & B
Ans: B

15. How can you comment using Razor Syntax?
A) *@ Comment me *@
B) @* Comment me *@
C) @* Comment me @*
D) *@ Comment me @*
E) None
Ans: B

16. Which Namespace is used for Razor View Engine ?
A) System.Web.Razor
B) System.Web.Mvc.WebFormViewEngine
C) Both A & B
D) None
Ans: A

17. Which Namespace is used for ASPX View Engine ?
A) System.Web.Razor
B) System.Web.Mvc.WebFormViewEngine
C) Both A & B
D) None
Ans: B

18. The Razor View Engine uses to render server side content.
A) @
B) <%= %>
C) Both A & B
D) None
Ans: A

19. The ASPX View Engine uses to render server side content.
A) @
B) <%= %>
C) Both A & B
D) None
Ans: B

20. Which is more faster between ASPX View Engine and Razor View Engine.
A) ASPX View Engine
B) Razor View Engine
C) Both A & B
D) None
Ans: A

21. Does Razor Engine supports for TDD ?
A) Yes
B) No
C) None
Ans: A

22. Does ASPX View Engine supports for TDD ?
A) Yes
B) No
C) None
Ans: B

22. How to Print value from Controller to View in MVC ?
A) ViewBag.ECMDetail = “my message”; and in view @ViewBag.ECMDetail
B) ViewBag.ECMDetail = “my message”; and in view ViewBag.ECMDetail
B) ViewBag.ECMDetail = “my message”; and in view ViewBag.Title
D) None
Ans: A

28. Are MVC and Web API merged into one in MVC 6?
A) Yes
B) No
C) Both A & B
D) None
Ans: A
29. Does MVC 6 introduced new JSON project based structure?
A) Yes
B) No
C) Both A & B
D) None
Ans: A

30. Does MVC 6 allow only save change, hitting the save but then refreshing the browser to reflect changes?
A) Yes
B) No
C) Both A & B
D) None
Ans: A

31. Does vNext is now Open Sourced via the .NET Foundation and open to public contributions.
A) Yes
B) No
C) Both A & B
D) None
Ans: A

32. Can vNext runs on both Mac and Linux today (Mono Version)?
A) Yes
B) No
C) Both A & B
D) None
Ans: A

34. How does work Viewstart in MVC (ASP.Net)?
A) Viestart is used to layout of the application.
B) Viewstart is used like Masterpage in traditional forms (ASP.Net pages).
C) Viewstart render first in the views.
D) A, B and C.
E) None
Ans: D

35. Viewstart comes under which folder name ?
A) Views
B) Account
C) Shared
D) Home
Ans: A
36. Does Viewstart override all Views layout/template under “Views” folder in MVC ?
A) Yes
B) No
C) Both A & B
D) None
Ans: A

37. What is the name of default Viewstart Page in ASP.Net MVC ?
A) _ViewStart.cshtml
B) _Layout.cshtml
C) _Login.cshtml
D) None
Ans: A

41. Which is the way to render Partial View using ASP.Net MVC Razor Engine?
A) @Html.Partial(“_PartialHeader”)
B) @Html.PartialView(“_PartialHeader”)
C) @Html.PartialHtml(“_PartialHeader”)
D) B and C
E) None
Ans: A

42. Which Namespace is used to “Display” in Data Annotation using MVC ?
A) System.ComponentModel
B) System.ComponentModel.DataAnnotations
C) Both A and B
D) None
Ans: A

43. Which Namespaces are required to Data Annotation using MVC ?
A) System.ComponentModel
B) System.ComponentModel.DataAnnotations
C) Both A and B
D) None
Ans: C

44. Are both TempData/ViewData require typecasting in MVC?
A) Both (TempData/ViewData) requires type casting to avoid null exception.
B) No, these (TempData/ViewData) does not require type casting.
C) Both A) & B)
D) None
Ans: A

45. Is ViewBag slower than ViewData in MVC?
A) Yes
B) No
C) Both A) & B)
D) None
Ans: A

46. Is ViewData faster than ViewBag in MVC?
A) Yes
B) No
C) Both A) & B)
D) None
Ans: A

47. Are both TempData/ViewData property of Controller base class in MVC?
A) Yes
B) No
C) Both A) & B)
D) None
Ans: A

48. Does TempData used to pass data from one page to another page in MVC?
A) Yes
B) No
C) Both A) & B)
D) None
Ans: A

49. Can ASP.Net Web API specialize to XML or JSON ?
A) Yes
B) No
C) None
Ans: A

50. Does Web API (ASP.Net) supports to non SOAP based like XML or JSON ?
A) Yes
B) No
C) None
Ans: A

51. Does Web API (ASP.Net) supports to both version mobile apps and others ?
A) Yes
B) No
C) Both A & B
D) None
Ans: A

52. Can ASP.Net Web API, it works HTTP standard verbs like POST, GET, PUT, DELETE (CRUD Operations) ?
A) Yes
B) No
C) Both A & B
D) None
Ans: A

53. Can ASP.Net Web API ability to both self hosting (outside of IIS) and IIS ?
A) Yes
B) No
C) None
Ans: A

54. Can ASP.Net Web API has ability to transport non HTTP protocols like TCP, UDP, Named Pipes etc ?
A) Yes
B) No
C) None
Ans: B

55. What is AuthConfig.cs in ASP.Net MVC ?
A) AuthConfig.cs is used to configure route settings
B) AuthConfig.cs is used to configure security settings including sites oAuth Login.
C) None
D) All
Ans: B

56. What is BundleConfig.cs in ASP.Net MVC ?
A) BundleConfig.cs in MVC is used to register filters for different purposes.
B) BundleConfig.cs in MVC is used to register bundles used by the bundling and minification, serveral bundles are added by default like jQuery, jQueryUI, jQuery validation, Modernizr, default CSS references.
C) All
D) None
Ans: B

57. What is FilterConfig.cs in ASP.Net MVC ?
A) FilterConfig.cs is used to register global MVC filters, HandleErrorAttribute is registered by default filter. We can also register other filters.
B) FilterConfig.cs is used to register global MVC bundles.
C) None
D) All
Ans: A

58. What is RouteConfig.cs in ASP.Net MVC?
A) RouteConfig.cs is used to register MVC config statements, route config.
B) RouteConfig.css is used to register global MVC bundles.
C) None
D) All
Ans: A

59. What is the difference between HtmlTextbox and HtmlTextboxFor using ASP.Net MVC Razor Engine?
A) @Html.TextBox is not strongly typed, @Html.TextBoxFor is strongly typed that is why should be use @Html.TextBoxFor in MVC Razor Engine.
B) @Html.TextBox is strongly typed, @Html.TextBoxFor is not strongly typed that is why should be use @Html.TextBox in MVC Razor Engine.
C) None
D) Both A and B
Ans: A

60. What is the benefits of Html.RenderPartial using ASP.Net MVC Razor Engine?
A) @Html.RenderPartial Returns response, moreover requires to create action.
B) @Html.RenderPartial Returns nothing (void), it is faster than @Html.Partial, moreover requires not to create action.
C) None
D) Both A and B
Ans: B

61. What is the benefits of Html.Partial using ASP.Net MVC Razor Engine?
A) @Html.RenderPartial Returns response, moreover requires to create action.
B) @Html.RenderPartial Returns string value, it is slower than @Html.RenderPartial, moreover requires not to create action.
C) None
D) Both A and B
Ans: B

62. How to check Request coming from which controller using MVC ASP.Net?
A) var _controller = HttpContext.Current.Request.RequestContext.Values[“Controller”].ToString();
B) var _controller = HttpContext.Current.Request.RequestContext.RouteData.Values[“Controller”].ToString();
C) var _controller = RouteData.Values[“Controller”].ToString();
D) None
Ans: B

63. For which ModelState.IsValid Validate ?
A) It checks for Entityframework Model state.
B) It checks for valid Model State using DataAnnotations.
C) It checks for SQL database state.
D) None
Ans: B

64. Which Name space is used to create chart using ASP.Net MVC?
A) using System.Web.MVC;
B) using System.Web.Helpers;
c) using System.Web.Chart;
D) All
Ans: B

65. How can we provide Height and Width to MVC Charts ?
A) new Chart(width – 600, height – 400)
B) new Chart(width = 600, height = 400)
C) new Chart(width: 600, height: 400)
D) All
Ans: C
66. How can we set theme to MVC Charts?
A) new Chart(width: 600, height: 400, theme: ChartTheme.Vanilla3D)
B) new Chart(width: 600, height: 400, theme: ChartTheme = Vanilla3D)
C) new Chart(width: 600, height: 400, theme: Vanilla3D)
D) None
Ans: A

67. How can we give Title to MVC Charts?
A) var chart = AddTitle(“My First Chart”)
B) .AddTitle(“My First Chart”)
C) .AddTitle(‘My First Chart’)
D) All
Ans: B

68. How can we add Series to MVC Charts?
A) .AddSeries(chartType: “Bar”, xValue: xValue, yValues: yValue)
B) .AddSeries(chartType: “Bar”, xValue = xValue, yValues = yValue)
C) .AddSeries(chartType: “Bar”, xValue: xValue, yValues: yValue)
D) None
Ans: A

69. How can we add Chart Type to MVC Charts?
A) .NewSeries(chartType: “Bar”)
B) .Series(chartType: “Bar”)
C) .AddSeries(chartType: “Bar”)
D) All
Ans: C

70. How can we write Chart output to MVC View?
A) .Write(bmp);
B) Write(“bmp”);
C) .Write(“bmp”);
D) All
Ans: C

72. Which name space using can send email in ASP.Net MVC?
A) using System.Net.Mail;
B) using System.Net;
C) using System.Mail;
D) None
Ans: A

73. If Razor View Engine need to add JQuery function and contain @ special character then how we can write it in Razor View?
A) Replace @ to @@@ (tripple)
B) Replace @ to @@ (double)
C) None
D) Both (A & B)
Ans: B

74. How to set Default Value to Hidden Input Box using ASP.Net MVC?
A) @Html.HiddenFor(m => m.Name, “Jack”)
B) @Html.HiddenFor(m => m.Name, new { Value = “Jack”})
C) @Html.Hidden(m => m.Name, new { Value = “Jack”})
D) None
Ans: B

75. How to check all errors of Model using ASP.Net MVC?
A) var errors = Model.Values.SelectMany(v => v.Errors);
B) var errors = ModelState.SelectMany(v => v.Errors);
C) var errors = ModelState.Values.SelectMany(v => v.Errors);
D) None
Ans: C

76. AuthConfig.cs file is under in which App folder ?
A) App_Data
B) App_Start
C) Content
D) Filters
Ans: B

77. BundleConfig.cs file is under in which App folder ?
A) App_Data
B) App_Start
C) Content
D) Filters
Ans: B

78. FilterConfig.cs file is under in which App folder ?
A) App_Data
B) App_Start
C) Content
D) Filters
Ans: B

79. RouteConfig.cs file is under in which App folder ?
A) App_Data
B) App_Start
C) Content
D) Filters
Ans:B

80. WebApiConfig.cs file is under in which App folder ?
A) App_Data
B) App_Start
C) Content
D) Filters
Ans: B

82. Which filter will be execute at first using ASP.Net MVC?
A) Action filters
B) Authorization filters
C) Response filters
D) Exception filters
Ans: B

83. Which filter will be execute at last using ASP.Net MVC?
A) Action filters
B) Authorization filters
C) Exception filters
D) Response filters
Ans: C

150 TOP C#.Net(C Sharp dotnet) Interview Questions and Answers pdf

Posted on 11th August 2016 By NaukriadminLeave a comment

Read the most frequently asked 150 top C Sharp dotnet interview questions and answers for freshers and experienced job interview questions pdf

C#.Net Dotnet Interview Questions and Answers List

1. What’s C# ?
C# (pronounced C-sharp) is a new object oriented language from Microsoft and is derived from C and C++. It also borrows a lot of concepts from Java too including garbage collection.

2. Is it possible to inline assembly or IL in C# code?
– No.

3. Is it possible to have different access modifiers on the get/set methods of a property?
– No. The access modifier on a property applies to both its get and set accessors. What you need to do if you want them to be different is make the property read-only (by only providing a get accessor) and create a private/internal set method that is separate from the property.

4. Is it possible to have a static indexer in C#? allowed in C#.
– No. Static indexers are not

5. If I return out of a try/finally in C#, does the code in the finally-clause run?
-Yes. The code in the finally always runs. If you return out of the try block, or even if you do a goto out of the try, the finally block always runs:
using System;
class main
{
public static void Main()
{
try
{
Console.WriteLine(\”In Try block\”);
return;
}
finally
{
Console.WriteLine(\”In Finally block\”);
}
}
}

Both In Try block and In Finally block will be displayed. Whether the return is in the try block or after the try-finally block, performance is not affected either way. The compiler treats it as if the return were outside the try block anyway. If it’s a return without an expression (as it is above), the IL emitted is identical whether the return is inside or outside of the try. If the return has an expression, there’s an extra store/load of the value of the expression (since it has to be computed within the try block).

6. I was trying to use an out int parameter in one of my functions. How should I declare the variable that I am passing to it?
You should declare the variable as an int, but when you pass it in you must specify it as ‘out’, like the following: int i; foo(out i); where foo is declared as follows:
[return-type] foo(out int o) { }

7. How does one compare strings in C#?
In the past, you had to call .ToString() on the strings when using the == or != operators to compare the strings’ values. That will still work, but the C# compiler now automatically compares the values instead of the references when the == or != operators are used on string types. If you actually do want to compare references, it can be done as follows: if ((object) str1 == (object) str2) { } Here’s an example showing how string compares work:
using System;
public class StringTest
{
public static void Main(string[] args)
{
Object nullObj = null; Object realObj = new StringTest();
int i = 10;
Console.WriteLine(\”Null Object is [\” + nullObj + \”]\n\”
+ \”Real Object is [\” + realObj + \”]\n\”
+ \”i is [\” + i + \”]\n\”);
// Show string equality operators
string str1 = \”foo\”;
string str2 = \”bar\”;
string str3 = \”bar\”;
Console.WriteLine(\”{0} == {1} ? {2}\”, str1, str2, str1 == str2 );
Console.WriteLine(\”{0} == {1} ? {2}\”, str2, str3, str2 == str3 );
}
}

Output:
Null Object is []
Real Object is [StringTest]
i is [10]
foo == bar ? False
bar == bar ? True

8. How do you specify a custom attribute for the entire assembly (rather than for a class)?
Global attributes must appear after any top-level using clauses and before the first type or namespace declarations. An example of this is as follows:
using System;
[assembly : MyAttributeClass] class X {}
Note that in an IDE-created project, by convention, these attributes are placed in AssemblyInfo.cs.

9. How do you mark a method obsolete?
[Obsolete] public int Foo() {…}
or
[Obsolete(\”This is a message describing why this method is obsolete\”)] public int Foo() {…}
Note: The O in Obsolete is always capitalized.
How do you implement thread synchronization (Object.Wait, Notify,and CriticalSection) in C#?
You want the lock statement, which is the same as Monitor Enter/Exit:
lock(obj) { // code }

translates to

try {
CriticalSection.Enter(obj);
// code
}
finally
{
CriticalSection.Exit(obj);
}

10. How do you directly call a native function exported from a DLL?
Here’s a quick example of the DllImport attribute in action:

using System.Runtime.InteropServices; \
class C
{
[DllImport(\”user32.dll\”)]
public static extern int MessageBoxA(int h, string m, string c, int type);
public static int Main()
{
return MessageBoxA(0, \”Hello World!\”, \”Caption\”, 0);
}
}

This example shows the minimum requirements for declaring a C# method that is implemented in a native DLL. The method C.MessageBoxA() is declared with the static and external modifiers, and has the DllImport attribute, which tells the compiler that the implementation comes from the user32.dll, using the default name of MessageBoxA. For more information, look at the Platform Invoke tutorial in the documentation.

11. How do I simulate optional parameters to COM calls?
You must use the Missing class and pass Missing.Value (in System.Reflection) for any values that have optional parameters.

12. What do you know about .NET assemblies?
Assemblies are the smallest units of versioning and deployment in the .NET application. Assemblies are also the building blocks for programs such as Web services, Windows services, serviced components, and .NET remoting applications.

13. What’s the difference between private and shared assembly?
Private assembly is used inside an application only and does not have to be identified by a strong name. Shared assembly can be used by multiple applications and has to have a strong name.

14. What’s a strong name?
A strong name includes the name of the assembly, version number, culture identity, and a public key token.

15. How can you tell the application to look for assemblies at the locations other than its own install?
Use the directive in the XML .config file for a given application.
< probing privatePath=c:\mylibs; bin\debug />
should do the trick. Or you can add additional search paths in the Properties box of the deployed application.

16. How can you debug failed assembly binds?
Use the Assembly Binding Log Viewer (fuslogvw.exe) to find out the paths searched.

17. Where are shared assemblies stored?
Global assembly cache.

18. How can you create a strong name for a .NET assembly?
With the help of Strong Name tool (sn.exe).

19. Where’s global assembly cache located on the system?
Usually C:\winnt\assembly or C:\windows\assembly.

20. Can you have two files with the same file name in GAC?
Yes, remember that GAC is a very special folder, and while normally you would not be able to place two files with the same name into a Windows folder, GAC differentiates by version number as well, so it’s possible for MyApp.dll and MyApp.dll to co-exist in GAC if the first one is version 1.0.0.0 and the second one is 1.1.0.0.

21. So let’s say I have an application that uses MyApp.dll assembly, version 1.0.0.0. There is a security bug in that assembly, and I publish the patch, issuing it under name MyApp.dll 1.1.0.0. How do I tell the client applications that are already installed to start using this new MyApp.dll?
Use publisher policy. To configure a publisher policy, use the publisher policy configuration file, which uses a format similar app .config file. But unlike the app .config file, a publisher policy file needs to be compiled into an assembly and placed in the GAC.

22. What is delay signing?
Delay signing allows you to place a shared assembly in the GAC by signing the assembly with just the public key. This allows the assembly to be signed with the private key at a later stage, when the development process is complete and the component or assembly is ready to be deployed. This process enables developers to work with shared assemblies as if they were strongly named, and it secures the private key of the signature from being accessed at different stages of development.

23. Is there an equivalent of exit() for quitting a C# .NET application?
Yes, you can use System.Environment.Exit(int exitCode) to exit the application or Application.Exit() if it’s a Windows Forms app.

24. Can you prevent your class from being inherited and becoming a base class for some other classes?
Yes, that is what keyword sealed in the class definition is for. The developer trying to derive from your class will get a message: cannot inherit from Sealed class WhateverBaseClassName. It is the same concept as final class in Java.

25. Is XML case-sensitive?
Yes, so and are different elements.
If a base class has a bunch of overloaded constructors, and an inherited class has another bunch of overloaded constructors, can you enforce a call from an inherited
26. constructor to an arbitrary base constructor?
Yes, just place a colon, and then keyword base (parameter list to invoke the appropriate constructor) in the overloaded constructor definition inside the inherited class.

27. I was trying to use an “out int” parameter in one of my functions. How should I declare the variable that I am passing to it?
You should declare the variable as an int, but when you pass it in you must specify it as ‘out’, like the following:
int i;
foo(out i);
where foo is declared as follows:
[return-type] foo(out int o) { }
How do I make a DLL in C#?
You need to use the /target:library compiler option.

28. How do I simulate optional parameters to COM calls?
You must use the Missing class and pass Missing.Value (in System.Reflection) for any values that have optional parameters.

29. Will finally block get executed if the exception had not occurred?
Yes.

30. What is the C# equivalent of C++ catch (…), which was a catch-all statement for any possible exception? Does C# support try-catch-finally blocks?
Yes. Try-catch-finally blocks are supported by the C# compiler. Here’s an example of a try-catch-finally block: using System;
public class TryTest
{
static void Main()
{
try
{
Console.WriteLine(“In Try block”);
throw new ArgumentException();
}
catch(ArgumentException n1)
{
Console.WriteLine(“Catch Block”);
}
finally
{
Console.WriteLine(“Finally Block”);
}
}
}
Output: In Try Block
Catch Block
Finally Block

31. If I return out of a try/finally in C#, does the code in the finally-clause run?
Yes. The code in the finally always runs. If you return out of the try block, or even if you do a “goto” out of the try, the finally block always runs, as shown in the following
example: using System;
class main
{
public static void Main()
{
try
{
Console.WriteLine(“In Try block”);
return;
}
finally
{
Console.WriteLine(“In Finally block”);
}
}
}

Both “In Try block” and “In Finally block” will be displayed. Whether the return is in the try block or after the try-finally block, performance is not affected either way. The compiler treats it as if the return were outside the try block anyway. If it’s a return without an expression (as it is above), the IL emitted is identical whether the return is inside or outside of the try. If the return has an expression, there’s an extra store/load of the value of the expression (since it has to be computed within the try block).

32. Is there regular expression (regex) support available to C# developers?
Yes. The .NET class libraries provide support for regular expressions. Look at the documentation for the System.Text.RegularExpressions namespace.

33. Is there a way to force garbage collection?
Yes. Set all references to null and then call System.GC.Collect(). If you need to have some objects destructed, and System.GC.Collect() doesn’t seem to be doing it for you, you can force finalizers to be run by setting all the references to the object to null and then calling System.GC.RunFinalizers().

34. Does C# support properties of array types?
Yes. Here’s a simple example: using System;
class Class1
{
private string[] MyField;
public string[] MyProperty
{
get { return MyField; }
set { MyField = value; }
}
}
class MainClass
{
public static int Main(string[] args)
{
Class1 c = new Class1();
string[] arr = new string[] {“apple”, “banana”};
c.MyProperty = arr;
Console.WriteLine(c.MyProperty[0]); // “apple”
return 0;
}
}

35. What connections does Microsoft SQL Server support?
Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and passwords)

36. What is a satellite assembly?
When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.

37. How is method overriding different from overloading?
When overriding, you change the method behavior for a derived class. Overloading simply involves having a method with the same name within the class.
When do you absolutely have to declare a class as abstract (as opposed to free-willed educated choice or decision based on UML diagram)?
When at least one of the methods in the class is abstract. When the class itself is inherited from an abstract class, but not all base abstract methods have been over-ridden.

38. Why would you use untrusted verification?
Web Services might use it, as well as non-Windows applications.

39. What is the implicit name of the parameter that gets passed into the class set method?
Value, and its datatype depends on whatever variable we are changing.

40. How do I register my code for use by classic COM clients?
Use the regasm.exe utility to generate a type library (if needed) and the necessary entries in the Windows Registry to make a class available to classic COM clients. Once a class is registered in the Windows Registry with regasm.exe, a COM client can use the class as though it were a COM class.

41. How do I do implement a trace and assert?
Use a conditional attribute on the method, as shown below:
class Debug
{
[conditional(“TRACE”)]
public void Trace(string s)
{
Console.WriteLine(s);
}
}
class MyClass
{
public static void Main()
{
Debug.Trace(“hello”);
}
}

In this example, the call to Debug.Trace() is made only if the preprocessor symbol TRACE is defined at the call site. You can define preprocessor symbols on the command line by using the /D switch. The restriction on conditional methods is that they must have void return type

42. How do I create a multi language, multi file assembly?
Unfortunately, this is currently not supported in the IDE. To do this from the command line, you must compile your projects into netmodules (/target:module on the C# compiler), and then use the command line tool al.exe (alink) to link these netmodules together.

43. C# provides a default constructor for me. I write a constructor that takes a string as a parameter, but want to keep the no parameter one. How many constructors should I write?
Two. Once you write at least one constructor, C# cancels the freebie constructor, and now you have to write one yourself, even if there is no implementation in

44. What is the equivalent to regsvr32 and regsvr32 /u a file in .NET development?
Try using RegAsm.exe. The general syntax would be: RegAsm. A good description of RegAsm and its associated switches is located in the .NET SDK docs. Just search on “Assembly Registration Tool”.Explain ACID rule of thumb for transactions.

Transaction must be Atomic (it is one unit of work and does not dependent on previous and following transactions), Consistent (data is either committed or roll back, no in-between case where something has been updated and something hasnot), Isolated (no transaction sees the intermediate results of the current transaction), Durable (the values persist if the data had been committed even if the system crashes right after).

45. Where is the output of TextWriterTraceListener redirected?
To the Console or a text file depending on the parameter passed to the constructor.

46. How do I create a multilanguage, single-file assembly?
This is currently not supported by Visual Studio .NET.

47. Why cannot you specify the accessibility modifier for methods inside the interface?
They all must be public. Therefore, to prevent you from getting the false impression that you have any freedom of choice, you are not allowed to specify any accessibility, it is public by default.

48. Is it possible to restrict the scope of a field/method of a class to the classes in the same namespace?
There is no way to restrict to a namespace. Namespaces are never units of protection. But if you’re using assemblies, you can use the ‘internal’ access modifier to restrict access to only within the assembly.

49. Why do I get a syntax error when trying to declare a variable called checked?
The word checked is a keyword in C#.

50. Why are there five tracing levels in System.Diagnostics.TraceSwitcher?
The tracing dumps can be quite verbose and for some applications that are constantly running you run the risk of overloading the machine and the hard drive there. Five levels range from None to Verbose, allowing to fine-tune the tracing activities.

51. What is the syntax for calling an overloaded constructor within a constructor (this() and constructorname() does not compile)?
The syntax for calling another constructor is as follows:
class B
{
B(int i)
{ }
}
class C : B
{
C() : base(5) // call base constructor B(5)
{ }
C(int i) : this() // call C()
{ }
public static void Main() {}
}

52. Why do I get a “CS5001: does not have an entry point defined” error when compiling?
The most common problem is that you used a lowercase ‘m’ when defining the Main method. The correct way to implement the entry point is as follows:
class test
{
static void Main(string[] args) {}
}

53. What does the keyword virtual mean in the method definition?
The method can be over-ridden.
What optimizations does the C# compiler perform when you use the /optimize+ compiler option?
The following is a response from a developer on the C# compiler team:
We get rid of unused locals (i.e., locals that are never read, even if assigned).
We get rid of unreachable code.
We get rid of try-catch w/ an empty try.
We get rid of try-finally w/ an empty try (convert to normal code…).
We get rid of try-finally w/ an empty finally (convert to normal code…).
We optimize branches over branches:
gotoif A, lab1
goto lab2:
lab1:
turns into: gotoif !A, lab2
lab1:
We optimize branches to ret, branches to next instruction, and branches to branches.

54. How can I create a process that is running a supplied native executable (e.g., cmd.exe)?
The following code should run the executable and wait for it to exit before
continuing: using System;
using System.Diagnostics;
public class ProcessTest {
public static void Main(string[] args) {
Process p = Process.Start(args[0]);
p.WaitForExit();
Console.WriteLine(args[0] + ” exited.”);
}
}
Remember to add a reference to System.Diagnostics.dll when you compile.

55. What is the difference between the System.Array.CopyTo() and System.Array.Clone()?
The first one performs a deep copy of the array, the second one is shallow.

56. How do I declare inout arguments in C#?
The equivalent of inout in C# is ref. , as shown in the following
example: public void MyMethod (ref String str1, out String str2)
{
…
}
When calling the method, it would be called like this: String s1;
String s2;
s1 = “Hello”;
MyMethod(ref s1, out s2);
Console.WriteLine(s1);
Console.WriteLine(s2);
Notice that you need to specify ref when declaring the function and calling it.

57. Is there a way of specifying which block or loop to break out of when working with nested loops?
The easiest way is to use goto: using System;
class BreakExample
{
public static void Main(String[] args)
{
for(int i=0; i<3; i++) { Console.WriteLine("Pass {0}: ", i); for( int j=0 ; j<100 ; j++ ) { if ( j == 10) goto done; Console.WriteLine("{0} ", j); } Console.WriteLine("This will not print"); } done: Console.WriteLine("Loops complete."); } } 58. What is the difference between const and static read-only? The difference is that static read-only can be modified by the containing class, but const can never be modified and must be initialized to a compile time constant. To expand on the static read-only case a bit, the containing class can only modify it: -- in the variable declaration (through a variable initializer). -- in the static constructor (instance constructors if it's not static). 59. What does the parameter Initial Catalog define inside Connection String? The database name to connect to. 60. What is the difference between System.String and System.StringBuilder classes? System.String is immutable; System.StringBuilder was designed with the purpose of having a mutable string where a variety of operations can be performed. 61. What is the top .NET class that everything is derived from? System.Object. 62. Can you allow class to be inherited, but prevent the method from being over-ridden? Yes, just leave the class public and make the method sealed 63. Can you change the value of a variable while debugging a C# application? Yes, if you are debugging via Visual Studio.NET, just go to Immediate window. 64. Are private class-level variables inherited? Yes, but they are not accessible, so looking at it you can honestly say that they are not inherited. But they are. 65. Can you inherit multiple interfaces? Yes. .NET does support multiple interfaces. 66. From a versioning perspective, what are the drawbacks of extending an interface as opposed to extending a class? With regard to versioning, interfaces are less flexible than classes. With a class, you can ship version 1 and then, in version 2, decide to add another method. As long as the method is not abstract (i.e., as long as you provide a default implementation of the method), any existing derived classes continue to function with no changes. Because interfaces do not support implementation inheritance, this same pattern does not hold for interfaces. Adding a method to an interface is like adding an abstract method to a base class--any class that implements the interface will break, because the class doesn't implement the new interface method. 67. Which one is trusted and which one is untrusted? Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction 68. What namespaces are necessary to create a localized application? System.Globalization, System.Resources. 69. Does Console.WriteLine() stop printing when it reaches a NULL character within a string? Strings are not null terminated in the runtime, so embedded nulls are allowed. Console.WriteLine() and all similar methods continue until the end of the string. 70. What is the advantage of using System.Text.StringBuilder over System.String? StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time it is being operated on, a new instance is created. 71. What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET? SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but it is a .NET layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines. 72. Why do I get a security exception when I try to run my C# app? Some security exceptions are thrown if you are working on a network share. There are some parts of the frameworks that will not run if being run off a share (roaming profile, mapped drives, etc.). To see if this is what's happening, just move the executable over to your local drive and see if it runs without the exceptions. One of the common exceptions thrown under these conditions is System.Security.SecurityException. To get around this, you can change your security policy for the intranet zone, code group 1.2, (the zone that running off shared folders falls into) by using the caspol.exe tool. 73. Is there any sample C# code for simple threading? Some sample code follows: using System; using System.Threading; class ThreadTest { public void runme() { Console.WriteLine("Runme Called"); } public static void Main(String[] args) { ThreadTest b = new ThreadTest(); Thread t = new Thread(new ThreadStart(b.runme)); t.Start(); } } 74. What is the difference between // comments, /* */ comments and /// comments? Single-line, multi-line and XML documentation comments. 75. What is the difference between and XML documentation tag? Single line code example and multiple-line code example. Explain the three services model (three-tier application). Presentation (UI), business (logic and underlying code) and data (from storage or other sources). What are three test cases you should go through in unit testing? Positive test cases (correct data, correct output), negative test cases (broken or missing data, proper handling), exception test cases (exceptions are thrown and caught properly). 76. How do you inherit from a class in C#? Place a colon and then the name of the base class. Notice that it is double colon in C++. 77. How do I port "synchronized" functions from Visual J++ to C#? Original Visual J++ code: public synchronized void Run() { // function body } Ported C# code: class C { public void Run() { lock(this) { // function body } } public static void Main() {} } 78. Can I define a type that is an alias of another type (like typedef in C++)? Not exactly. You can create an alias within a single file with the "using" directive: using System; using Integer = System.Int32; // alias But you can't create a true alias, one that extends beyond the file in which it is declared. Refer to the C# spec for more info on the 'using' statement's scope. 79. Is it possible to have different access modifiers on the get/set methods of a property? No. The access modifier on a property applies to both its get and set accessors. What you need to do if you want them to be different is make the property read-only (by only providing a get accessor) and create a private/internal set method that is separate from the property. 80. Is it possible to have a static indexer in C#? No. Static indexers are not allowed in C#. 81. Does C# support #define for defining global constants? No. If you want to get something that works like the following C code: #define A 1 use the following C# code: class MyConstants { public const int A = 1; } Then you use MyConstants.A where you would otherwise use the A macro. Using MyConstants.A has the same generated code as using the literal 1. 82. Does C# support templates? No. However, there are plans for C# to support a type of template known as a generic. These generic types have similar syntax but are instantiated at run time as opposed to compile time. You can read more about them here. 83. Does C# support parameterized properties? No. C# does, however, support the concept of an indexer from language spec. An indexer is a member that enables an object to be indexed in the same way as an array. Whereas properties enable field-like access, indexers enable array-like access. As an example, consider the Stack class presented earlier. The designer of this class may want to expose array-like access so that it is possible to inspect or alter the items on the stack without performing unnecessary Push and Pop operations. That is, Stack is implemented as a linked list, but it also provides the convenience of array access. Indexer declarations are similar to property declarations, with the main differences being that indexers are nameless (the name used in the declaration is this, since this is being indexed) and that indexers include indexing parameters. The indexing parameters are provided between square brackets. 84. Does C# support C type macros? No. C# does not have macros. Keep in mind that what some of the predefined C macros (for example, __LINE__ and __FILE__) give you can also be found in .NET classes like System.Diagnostics (for example, StackTrace and StackFrame), but they'll only work on debug builds. 85. Can you store multiple data types in System.Array? No. 86. Is it possible to inline assembly or IL in C# code? No. 87. Can you declare the override method static while the original method is non-static? No, you cannot, the signature of the virtual method must remain the same, only the keyword virtual is changed to keyword override 88. Does C# support multiple inheritance? No, use interfaces instead. 89. Can multiple catch blocks be executed? No, once the proper catch code fires off, the control is transferred to the finally block (if there are any), and then whatever follows the finally block. 90. Can you override private virtual methods? No, moreover, you cannot access private methods in inherited classes, have to be protected in the base class to allow any sort of access. 91. What is a pre-requisite for connection pooling? Multiple processes must agree that they will share the same connection, where every parameter is the same, 92. What is the data provider name to connect to Access database? Microsoft.Access. 93. Why does my Windows application pop up a console window every time I run it? Make sure that the target type set in the project properties setting is set to Windows Application, and not Console Application. If you're using the command line, compile with /target:winexe & not target:exe. 94. What is the wildcard character in SQL? Let us say you want to query database with LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve La%. 95. What is the role of the DataReader class in ADO.NET connections? It returns a read-only dataset from the data source when the command is executed. 96. What does the This window show in the debugger? It points to the object that is pointed to by this reference. Object’s instance data is shown. 97. Describe the accessibility modifier protected internal? It is available to derived classes and classes within the same Assembly (and naturally from the base class it is declared in). 98. What is an interface class? It is an abstract class with public abstract methods all of which must be implemented in the inherited classes. 99. What is a multicast delegate? It is a delegate that points to and eventually fires off several methods. 100. How does one compare strings in C#? In the past, you had to call .ToString() on the strings when using the == or != operators to compare the strings' values. That will still work, but the C# compiler now automatically compares the values instead of the references when the == or != operators are used on string types. If you actually do want to compare references, it can be done as follows: if ((object) str1 == (object) str2) { ... } Here's an example showing how string compares work: using System; public class StringTest { public static void Main(string[] args) { Object nullObj = null; Object realObj = new StringTest(); int i = 10; Console.WriteLine("Null Object is [" + nullObj + "]n" + "Real Object is [" + realObj + "]n" + "i is [" + i + "]n"); // Show string equality operators string str1 = "foo"; string str2 = "bar"; string str3 = "bar"; Console.WriteLine("{0} == {1} ? {2}", str1, str2, str1 == str2 ); Console.WriteLine("{0} == {1} ? {2}", str2, str3, str2 == str3 ); } } Output: Null Object is [] Real Object is [StringTest] i is [10] foo == bar ? False bar == bar ? True 101. What does assert() do? In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true. 102. How do I get deterministic finalization in C#? In a garbage collected environment, it's impossible to get true determinism. However, a design pattern that we recommend is implementing IDisposable on any class that contains a critical resource. Whenever this class is consumed, it may be placed in a using statement, as shown in the following example: using(FileStream myFile = File.Open(@"c:temptest.txt", FileMode.Open)) { int fileOffset = 0; while(fileOffset < myFile.Length) { Console.Write((char)myFile.ReadByte()); fileOffset++; } } When myFile leaves the lexical scope of the using, its dispose method will be called. 103. How can I get around scope problems in a try/catch? If you try to instantiate the class inside the try, it'll be out of scope when you try to access it from the catch block. A way to get around this is to do the following: Connection conn = null; try { conn = new Connection(); conn.Open(); } finally { if (conn != null) conn.Close(); } By setting it to null before the try block, you avoid getting the CS0165 error (Use of possibly unassigned local variable 'conn'). 104. Why do I get an error (CS1006) when trying to declare a method without specifying a return type? If you leave off the return type on a method declaration, the compiler thinks you are trying to declare a constructor. So if you are trying to declare a method that returns nothing, use void. The following is an example: // This results in a CS1006 error public static staticMethod (mainStatic obj) // This will work as wanted public static void staticMethod (mainStatic obj) 105. How do I convert a string to an int in C#? Here's an example: using System; class StringToInt { public static void Main() { String s = "105"; int x = Convert.ToInt32(s); Console.WriteLine(x); } } 106. How do you directly call a native function exported from a DLL? Here's a quick example of the DllImport attribute in action: using System.Runtime.InteropServices; class C { [DllImport("user32.dll")] public static extern int MessageBoxA(int h, string m, string c, int type); public static int Main() { return MessageBoxA(0, "Hello World!", "Caption", 0); } } This example shows the minimum requirements for declaring a C# method that is implemented in a native DLL. The method C.MessageBoxA() is declared with the static and external modifiers, and has the DllImport attribute, which tells the compiler that the implementation comes from the user32.dll, using the default name of MessageBoxA. For more information, look at the Platform Invoke tutorial in the documentation. 107. What is the .NET datatype that allows the retrieval of data by a unique key? HashTable. 108. How do you specify a custom attribute for the entire assembly (rather than for a class)? Global attributes must appear after any top-level using clauses and before the first type or namespace declarations. An example of this is as follows: using System; [assembly : MyAttributeClass] class X {} Note that in an IDE-created project, by convention, these attributes are placed in AssemblyInfo.cs. 109. What is the difference between a struct and a class in C#? From language spec: The list of similarities between classes and structs is as follows. Longstructs can implement interfaces and can have the same kinds of members as classes. Structs differ from classes in several important ways; however, structs are value types rather than reference types, and inheritance is not supported for structs. Struct values are stored on the stack or in-line. Careful programmers can sometimes enhance performance through judicious use of structs. For example, the use of a struct rather than a class for a Point can make a large difference in the number of memory allocations performed at runtime. The program below creates and initializes an array of 100 points. With Point implemented as a class, 101 separate objects are instantiated-one for the array and one each for the 100 elements. 110. What is the difference between the Debug class and Trace class? Documentation looks the same. Use Debug class for debug builds, use Trace class for both debug and release builds. 120. How can you overload a method? Different parameter data types, different number of parameters, different order of parameters. 121. What debugging tools come with the .NET SDK? CorDBG - command-line debugger, and DbgCLR - graphic debugger. Visual Studio .NET uses the DbgCLR. To use CorDbg, you must compile the original C# file using the /debug switch. 122. What does Dispose method do with the connection object? Deletes it from the memory. 123. How do you generate documentation from the C# file commented properly with a command-line compiler? Compile it with a /doc switch. 124. When you inherit a protected class-level variable, who is it available to? Classes in the same namespace. 125. How can I get the ASCII code for a character in C#? Casting the char to an int will give you the ASCII value: char c = 'f'; System.Console.WriteLine((int)c); or for a character in a string: System.Console.WriteLine((int)s[3]); The base class libraries also offer ways to do this with the Convert class or Encoding classes if you need a particular encoding. 126. Is there an equivalent to the instanceof operator in Visual J++? C# has the is operator: expr is type How do I create a Delegate/MulticastDelegate? C# requires only a single parameter for delegates: the method address. Unlike other languages, where the programmer must specify an object reference and the method to invoke, C# can infer both pieces of information by just specifying the method's name. For example, let's use System.Threading.ThreadStart: Foo MyFoo = new Foo(); ThreadStart del = new ThreadStart(MyFoo.Baz); This means that delegates can invoke static class methods and instance methods with the exact same syntax! 127. How do destructors and garbage collection work in C#? C# has finalizers (similar to destructors except that the runtime doesn't guarantee they'll be called), and they are specified as follows: class C { ~C() { // your code } public static void Main() {} } Currently, they override object.Finalize(), which is called during the GC process. 128. My switch statement works differently! Why? C# does not support an explicit fall through for case blocks. The following code is not legal and will not compile in C#: switch(x) { case 0: // do something case 1: // do something in common with 0 default: // do something in common with //0, 1 and everything else break; } To achieve the same effect in C#, the code must be modified as shown below (notice how the control flows are explicit): class Test { public static void Main() { int x = 3; switch(x) { case 0: // do something goto case 1; case 1: // do something in common with 0 goto default; default: // do something in common with 0, 1, and anything else break; } } } 129. How can I access the registry from C# code? By using the Registry and RegistryKey classes in Microsoft.Win32, you can easily access the registry. The following is a sample that reads a key and displays its value: using System;using Microsoft.Win32; class regTest { public static void Main(String[] args) { RegistryKey regKey; Object value; regKey = Registry.LocalMachine; regKey = regKey.OpenSubKey("HARDWAREDESCRIPTIONSystemCentralProcessor "); value = regKey.GetValue("VendorIdentifier"); Console.WriteLine("The central processor of this machine is: {0}.", value); } } 130. How can you sort the elements of the array in descending order? By calling Sort() and then Reverse() methods. 131. How do you debug an ASP.NET Web application? Attach the aspnet_wp.exe process to the DbgClr debugger. 132. How do you mark a method obsolete? Assuming you've done a "using System;": [Obsolete] public int Foo() {...} or [Obsolete("This is a message describing why this method is obsolete")] public int Foo() {...} Note: The O in Obsolete is capitalized. 133. How is the DLL Hell problem solved in .NET? Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly 134. What are the ways to deploy an assembly? An MSI installer, a CAB archive, and XCOPY command. 135. Why does DllImport not work for me? All methods marked with the DllImport attribute must be marked as public static extern. 136. What is a delegate? A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers. 137. What is the difference between an interface and abstract class? In the interface all methods must be abstract; in the abstract class some methods can be concrete. In the interface no accessibility modifiers are allowed, which is ok in abstract classes. 138. What is an abstract class? A class that cannot be instantiated. A concept in C++ known as pure virtual method. A class that must be inherited and have the methods over-ridden. Essentially, it is a blueprint for a class without any implementation. _break 139. Does C# support multiple-inheritance? No. 140. Who is a protected class-level variable available to? It is available to any sub-class (a class inheriting this class). 141. Can you store multiple data types in System.Array? No. 142. What’s the top .NET class that everything is derived from? System.Object. 143. What does the term immutable mean? The data value may not be changed. Note: The variable value may be changed, but the original immutable data value was discarded and a new data value was created in memory. 144. What’s the difference between System.String and System.Text.StringBuilder classes? System.String is immutable. System.StringBuilder was designed with the purpose of having a mutable string where a variety of operations can be performed. 145. What’s the advantage of using System.Text.StringBuilder over System.String? StringBuilder is more efficient in cases where there is a large amount of string manipulation. Strings are immutable, so each time a string is changed, a new instance in memory is created. 146. What’s the difference between the System.Array.CopyTo() and System.Array.Clone()? The first one performs a deep copy of the array, the second one is shallow. A shallow copy of an Array copies only the elements of the Array, whether they are reference types or value types, but it does not copy the objects that the references refer to. The references in the new Array point to the same objects that the references in the original Array point to. In contrast, a deep copy of an Array copies the elements and everything directly or indirectly referenced by the elements. 147. How can you sort the elements of the array in descending order? By calling Sort() and then Reverse() methods. 148. What’s the .NET collection class that allows an element to be accessed using a unique key? HashTable. 149. What class is underneath the SortedList class? A sorted HashTable. 150. Will the finally block get executed if an exception has not occurred? Yes.

101 MVC ASP Dotnet Multiple choice Questions and Answers pdf

Posted on 11th August 2016 By NaukriadminLeave a comment

Read the most frequently asked 101 top MVC multiple choice questions and answers PDF for freshers and experienced

ASP.Net MVC Interview Questions and Answers List

1. Which is the best approach to assign a session in MVC?
A) System.Web.HttpContext.Current.Session[“LoginID”] =7;
B) Current.Session[“LoginID”] =7;
C) Session[“LoginID”] =7;
D) None
Ans: B