1. What are the new Data Controls in Asp.net 2.0?
Data access in ASP.NET 2.0 can be accomplished completely declaratively (no code) using the new data-bound and data source controls. There are new data source controls to represent different data backends such as SQL database, business objects, and XML, and there are new data-bound controls for rendering common UI for data, such as gridview, detailsview, and formview.
2. What are the new Navigation Controls in Asp.net 2.0?
The navigation controls provide common UI for navigating between pages in your site, such as treeview, menu, and sitemappath. These controls use the site navigation service in ASP.NET 2.0 to retrieve the custom structure you have defined for your site.
3. What are the new Login Controlsin Asp.net 2.0?
The new login controls provide the building blocks to add authentication and authorization-based UI to your site, such as login forms, create user forms, password retrieval, and custom UI for logged in users or roles. These controls use the built-in membership and role services in ASP.NET 2.0 to interact with the user and role information defined for your site.
4. What are the new Web Part Controls in Asp.net 2.0 ?
Web parts are an exciting new family of controls that enable you to add rich, personalized content and layout to your site, as well as the ability to edit that content and layout directly from your application pages. These controls rely on the personalization services in ASP.NET 2.0 to provide a unique experience for each user in your application.
5. What are Master Pages?
This feature provides the ability to define common structure and interface elements for your site, such as a page header, footer, or navigation bar, in a common location called a "master page", to be shared by many pages in your site. In one simple place you can control the look, feel, and much of functionality for an entire Web site. This improves the maintainability of your site and avoids unnecessary duplication of code for shared site structure or behavior.
6. What are Themes and Skins in 2.0, explain usgae scenario?
The themes and skins features in ASP.NET 2.0 allow for easy customization of your site's look-and-feel. You can define style information in a common location called a "theme", and apply that style information globally to pages or controls in your site. Like Master Pages, this improves the maintainability of your site and avoid unnecessary duplication of code for shared styles.
7. What is a profile object, why is it used?
Using the new personalization services in ASP.NET 2.0 you can easily create customized experiences within Web applications. The Profile object enables developers to easily build strongly-typed, sticky data stores for user accounts and build highly customized, relationship based experiences. At the same time, a developer can leverage Web Parts and the personalization service to enable Web site visitors to completely control the layout and behavior of the site, with the knowledge that the site is completely customized for them. Personalizaton scenarios are now easier to build than ever before and require significantly less code and effort to implement.
8. What is Configuration API?
ASP.NET 2.0 contains new configuration management APIs, enabling users to programmatically build programs or scripts that create, read, and update Web.config and machine.config configuration files.
9. What is MMC Admin Tool?
ASP.NET 2.0 provides a new comprehensive admin tool that plugs into the existing IIS Administration MMC, enabling an administrator to graphically read or change common settings within our XML configuration files.
10. Explain the use of Pre-compilation Tool?
ASP.NET 2.0 delivers a new application deployment utility that enables both developers and administrators to precompile a dynamic ASP.NET application prior to deployment. This precompilation automatically identifies any compilation issues anywhere within the site, as well as enables ASP.NET applications to be deployed without any source being stored on the server (one can optionally remove the content of .aspx files as part of the compile phase), further protecting your intellectual property.
11. How is application management and maintenance improved in Asp.net 2.0?
ASP.NET 2.0 also provides new health-monitoring support to enable administrators to be automatically notified when an application on a server starts to experience problems. New tracing features will enable administrators to capture run-time and request data from a production server to better diagnose issues. ASP.NET 2.0 is delivering features that will enable developers and administrators to simplify the day-to-day management and maintenance of their Web applications.
12. What are Provider-driven Application Services? explain in detail?
ASP.NET 2.0 now includes built-in support for membership (user name/password credential storage) and role management services out of the box. The new personalization service enables quick storage/retrieval of user settings and preferences, facilitating rich customization with minimal code. The new site navigation system enables developers to quickly build link structures consistently across a site. As all of these services are provider-driven, they can be easily swapped out and replaced with your own custom implementation. With this extensibility option, you have complete control over the data store and schema that drives these rich application services.
13. Explain Server Control Extensibility with reference to Asp.net 2.0 ?
ASP.NET 2.0 includes improved support for control extensibility, such as more base classes that encapsulate common behaviors, improved designer support, more APIs for interacting with client-side script, metadata-driven support for new features like themes and accessibility verification, better state management, and more.
14. What are the Data Source Controls?
Data access in ASP.NET 2.0 is now performed declaratively using data source controls on a page. In this model, support for new data backend storage providers can be easily added by implementing custom data source controls. Additionally, the SqlDataSource control that ships in the box has built-in support for any ADO.NET managed provider that implements the new provider factory model in ADO.NET.
15. What are Compilation Build Providers?
Dynamic compilation in ASP.NET 2.0 is now handled by extensible compilation build providers, which associate a particular file extension with a handler that knows how to compile that extension dynamically at runtime. For example, .resx files can be dynamically compiled to resources, .wsdl files to web service proxies, and .xsd files to typed DataSet objects. In addition to the built-in support, it is easy to add support for additional extensions by implementing a custom build provider and registering it in Web.config.
16. What is Expression Builders, why would you use it?
ASP.NET 2.0 introduces a declarative new syntax for referencing code to substitute values into the page, called Expression Builders. ASP.NET 2.0 includes expression builders for referencing string resources for localization, connection strings, application settings, and profile values. You can also write your own expression builders to create your own custom syntax to substitute values in a page rendering.
17. Is ASP.NET 64-Bit enabled? how?
ASP.NET 2.0 is now 64-bit enabled, meaning it can take advantage of the full memory address space of new 64-bit processors and servers. Developers can simply copy existing 32-bit ASP.NET applications onto a 64-bit ASP.NET 2.0 server and have them automatically be JIT compiled and executed as native 64-bit applications (no source code changes or manual re-compile are required).
18. Explain how Caching in Asp.net 2.0 is different from Caching in Asp.net 1.1?
ASP.NET 2.0 also now includes automatic database server cache invalidation. This powerful and easy-to-use feature allows developers to aggressively output cache database-driven page and partial page content within a site and have ASP.NET automatically invalidate these cache entries and refresh the content whenever the back-end database changes. Developers can now safely cache time-critical content for long periods without worrying about serving visitors stale data.
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Friday, January 9, 2009
ASP.net Interview Questions
What is polymorphism?
Polymorphism means allowing a single definition to be used with different types of data (specifically, different classes of objects). For example, a polymorphic function definition can replace several type-specific ones, and a single polymorphic operator can act in expressions of various types. Many programming languages implement some forms of polymorphism.
The concept of polymorphism applies to data types in addition to functions. A function that can evaluate to and be applied to values of different types is known as a polymorphic function. A data type that contains elements of different types is known as a polymorphic data type.
Polymorphism may be achieved by overloading a function, overloading an operator, changing the order of types, changing the types using the same name for the member in context.
Example:
Public Class Calc
{
public void fnMultiply(int x, int y)
{ return x * y; }
public void fnMultiply(int x, int y, int z)
{ return x * y * z; }
}
...
...
Calc obj;
int Result;
Result = obj.fnMultiply(2,3,4); // The second fnMultiply would be called
Result = obj.fnMultiply(3,4); // The first fnMultiply would be called
//Here, the call depends on the number of parameters passed, polymorphism is achieved using overloading
Short Answer .NET Interview Questions (PAGE 1)
Q1. Explain the differences between Server-side and Client-side code?
Ans. Server side code will execute at server (where the website is hosted) end, & all the business logic will execute at server end where as client side code will execute at client side (usually written in javascript, vbscript, jscript) at browser end.
Q2. What type of code (server or client) is found in a Code-Behind class?
Ans. Server side code.
Q3. How to make sure that value is entered in an asp:Textbox control?
Ans. Use a RequiredFieldValidator control.
Q4. Which property of a validation control is used to associate it with a server control on that page?
Ans. ControlToValidate property.
Q5. How would you implement inheritance using VB.NET & C#?
Ans. C# Derived Class : Baseclass
VB.NEt : Derived Class Inherits Baseclass
Q6. Which method is invoked on the DataAdapter control to load the generated dataset with data?
Ans. Fill() method.
Q7. What method is used to explicitly kill a user's session?
Ans. Session.Abandon()
Q8. What property within the asp:gridview control is changed to bind columns manually?
Ans. Autogenerated columns is set to false
Q9. Which method is used to redirect the user to another page without performing a round trip to the client?
Ans. Server.Transfer method.
Q10. How do we use different versions of private assemblies in same application without re-build?
Ans.Inside the Assemblyinfo.cs or Assemblyinfo.vb file, we need to specify assembly version.
assembly: AssemblyVersion
Q11. Is it possible to debug java-script in .NET IDE? If yes, how?
Ans. Yes, simply write "debugger" statement at the point where the breakpoint needs to be set within the javascript code and also enable javascript debugging in the browser property settings.
Q12. How many ways can we maintain the state of a page?
Ans. 1. Client Side - Query string, hidden variables, viewstate, cookies
2. Server side - application , cache, context, session, database
Q13. What is the use of a multicast delegate?
Ans. A multicast delegate may be used to call more than one method.
Q14. What is the use of a private constructor?
Ans. A private constructor may be used to prevent the creation of an instance for a class.
Q15. What is the use of Singleton pattern?
Ans. A Singleton pattern .is used to make sure that only one instance of a class exists.
Q16. When do we use a DOM parser and when do we use a SAX parser?
Ans. The DOM Approach is useful for small documents in which the program needs to process a large portion of the document whereas the SAX approach is useful for large documents in which the program only needs to process a small portion of the document.
Q17. Will the finally block be executed if an exception has not occurred?
Ans.Yes it will execute.
Q18. What is a Dataset?
Ans. A dataset is an in memory database kindof object that can hold database information in a disconnected environment.
Q19. Is XML a case-sensitive markup language?
Ans. Yes.
Q20. What is an .ashx file?
Ans. It is a web handler file that produces output to be consumed by an xml consumer client (rather than a browser).
Short Answer .NET Interview Questions (PAGE 2)
Q21. What is encapsulation?
Ans. Encapsulation is the OOPs concept of binding the attributes and behaviors in a class, hiding the implementation of the class and exposing the functionality.
Q22. What is Overloading?
Ans. When we add a new method with the same name in a same/derived class but with different number/types of parameters, the concept is called overluoad and this ultimately implements Polymorphism.
Q23. What is Overriding?
Ans. When we need to provide different implementation in a child class than the one provided by base class, we define the same method with same signatures in the child class and this is called overriding.
Q24. What is a Delegate?
Ans. A delegate is a strongly typed function pointer object that encapsulates a reference to a method, and so the function that needs to be invoked may be called at runtime.
Q25. Is String a Reference Type or Value Type in .NET?
Ans. String is a Reference Type object.
Q26. What is a Satellite Assembly?
Ans. Satellite assemblies contain resource files corresponding to a locale (Culture + Language) and these assemblies are used in deploying an application globally for different languages.
Q27. What are the different types of assemblies and what is their use?
Ans. Private, Public(also called shared) and Satellite Assemblies.
Q28. Are MSIL and CIL the same thing?
Ans. Yes, CIL is the new name for MSIL.
Q29. What is the base class of all web forms?
Ans. System.Web.UI.Page
Q30. How to add a client side event to a server control?
Ans. Example... BtnSubmit.Attributes.Add("onclick","javascript:fnSomeFunctionInJavascript()");
Q31. How to register a client side script from code-behind?
Ans. Use the Page.RegisterClientScriptBlock method in the server side code to register the script that may be built using a StringBuilder.
Q32. Can a single .NET DLL contain multiple classes?
Ans. Yes, a single .NET DLL may contain any number of classes within it.
Q33. What is DLL Hell?
Ans. DLL Hell is the name given to the problem of old unmanaged DLL's due to which there was a possibility of version conflict among the DLLs.
Q34. can we put a break statement in a finally block?
Ans. The finally block cannot have the break, continue, return and goto statements.
Q35. What is a CompositeControl in .NET?
Ans. CompositeControl is an abstract class in .NET that is inherited by those web controls that contain child controls within them.
Q36. Which control in asp.net is used to display data from an xml file and then displayed using XSLT?
Ans. Use the asp:Xml control and set its DocumentSource property for associating an xml file, and set its TransformSource property to set the xml control's xsl file for the XSLT transformation.
Q37. Can we run ASP.NET 1.1 application and ASP.NET 2.0 application on the same computer?
Ans. Yes, though changes in the IIS in the properties for the site have to be made during deployment of each.
Q38. What are the new features in .NET 2.0?
Ans. Plenty of new controls, Generics, anonymous methods, partial classes, iterators, property visibility (separate visibility for get and set) and static classes.
Q39. Can we pop a MessageBox in a web application?
Ans. Yes, though this is done clientside using an alert, prompt or confirm or by opening a new web page that looks like a messagebox.
Q40. What is managed data?
Ans. The data for which the memory management is taken care by .Net runtime’s garbage collector, and this includes tasks for allocation de-allocation.
Short Answer .NET Interview Questions (PAGE 3)
Q41. How to instruct the garbage collector to collect unreferenced data?
Ans. We may call the garbage collector to collect unreferenced data by executing the System.GC.Collect() method.
Q42. How can we set the Focus on a control in ASP.NET?
Ans. txtBox123.Focus(); OR Page.SetFocus(NameOfControl);
Q43. What are Partial Classes in Asp.Net 2.0?
Ans. In .NET 2.0, a class definition may be split into multiple physical files but partial classes do not make any difference to the compiler as during compile time, the compiler groups all the partial classes and treats them as a single class.
Q44. How to set the default button on a Web Form?
Ans.
Q45.Can we force the garbage collector to run?
Ans. Yes, using the System.GC.Collect(), the garbage collector is forced to run in case required to do so.
Q46. What is Boxing and Unboxing?
Ans. Boxing is the process where any value type can be implicitly converted to a reference type object while Unboxing is the opposite of boxing process where the reference type is converted to a value type.
Q47. What is Code Access security? What is CAS in .NET?
Ans. CAS is the feature of the .NET security model that determines whether an application or a piece of code is permitted to run and decide the resources it can use while running.
Q48. What is Multi-tasking?
Ans. It is a feature of operating systems through which multiple programs may run on the operating system at the same time, just like a scenario where a Notepad, a Calculator and the Control Panel are open at the same time.
Q49. What is Multi-threading?
Ans. When an application performs different tasks at the same time, the application is said to exhibit multithreading as several threads of a process are running.2
Q50. What is a Thread?
Ans. A thread is an activity started by a process and its the basic unit to which an operating system allocates processor resources.
Q51. What does AddressOf in VB.NET operator do?
Ans. The AddressOf operator is used in VB.NET to create a delegate object to a method in order to point to it.
Q52. How to refer to the current thread of a method in .NET?
Ans. In order to refer to the current thread in .NET, the Thread.CurrentThread method can be used. It is a public static property.
Q53. How to pause the execution of a thread in .NET?
Ans. The thread execution can be paused by invoking the Thread.Sleep(IntegerValue) method where IntegerValue is an integer that determines the milliseconds time frame for which the thread in context has to sleep.
Q54. How can we force a thread to sleep for an infinite period?
Ans. Call the Thread.Interupt() method.
Q55. What is Suspend and Resume in .NET Threading?
Ans. Just like a song may be paused and played using a music player, a thread may be paused using Thread.Suspend method and may be started again using the Thread.Resume method. Note that sleep method immediately forces the thread to sleep whereas the suspend method waits for the thread to be in a persistable position before pausing its activity.
Q56. How can we prevent a deadlock in .Net threading?
Ans. Using methods like Monitoring, Interlocked classes, Wait handles, Event raising from between threads, using the ThreadState property.
Q57. What is Ajax?
Ans. Asyncronous Javascript and XML - Ajax is a combination of client side technologies that sets up asynchronous communication between the user interface and the web server so that partial page rendering occur instead of complete page postbacks.
Q58. What is XmlHttpRequest in Ajax?
Ans. It is an object in Javascript that allows the browser to communicate to a web server asynchronously without making a postback.
Q59. What are the different modes of storing an ASP.NET session?
Ans. InProc (the session state is stored in the memory space of the Aspnet_wp.exe process but the session information is lost when IIS reboots), StateServer (the Session state is serialized and stored in a separate process call Viewstate is an object in .NET that automatically persists control setting values across the multiple requests for the same page and it is internally maintained as a hidden field on the web page though its hashed for security reasons.
Q60. What is a delegate in .NET?
Ans. A delegate in .NET is a class that can have a reference to a method, and this class has a signature that can refer only those methods that have a signature which complies with the class.
Short Answer .NET Interview Questions (PAGE 4)
Q61. Is a delegate a type-safe functions pointer?
Ans. Yes
Q62. What is the return type of an event in .NET?
Ans. There is No return type of an event in .NET.
Q63. Is it possible to specify an access specifier to an event in .NET?
Ans. Yes, though they are public by default.
Q64. Is it possible to create a shared event in .NET?
Ans. Yes, but shared events may only be raised by shared methods.
Q65. How to prevent overriding of a class in .NET?
Ans. Use the keyword NotOverridable in VB.NET and sealed in C#.
Q66. How to prevent inheritance of a class in .NET?
Ans. Use the keyword NotInheritable in VB.NET and sealed in C#.
Q67. What is the purpose of the MustInherit keyword in VB.NET?
Ans. MustInherit keyword in VB.NET is used to create an abstract class.
Q68. What is the access modifier of a member function of in an Interface created in .NET?
Ans. It is always public, we cant use any other modifier other than the public modifier for the member functions of an Interface.
Q69. What does the virtual keyword in C# mean?
Ans. The virtual keyword signifies that the method and property may be overridden.
Q70. How to create a new unique ID for a control?
Ans. ControlName.ID = "ControlName" + Guid.NewGuid().ToString(); //Make use of the Guid class
Q71A. What is a HashTable in .NET?
Ans. A Hashtable is an object that implements the IDictionary interface, and can be used to store key value pairs. The key may be used as the index to access the values for that index.
Q71B. What is an ArrayList in .NET?
Ans. Arraylist object is used to store a list of values in the form of a list, such that the size of the arraylist can be increased and decreased dynamically, and moreover, it may hold items of different types. Items in an arraylist may be accessed using an index.
Q72. What is the value of the first item in an Enum? 0 or 1?
Ans. 0
Q73. Can we achieve operator overloading in VB.NET?
Ans. Yes, it is supported in the .NET 2.0 version, the "operator" keyword is used.
Q74. What is the use of Finalize method in .NET?
Ans. .NET Garbage collector performs all the clean up activity of the managed objects, and so the finalize method is usually used to free up the unmanaged objects like File objects, Windows API objects, Database connection objects, COM objects etc.
Q75. How do you save all the data in a dataset in .NET?
Ans. Use the AcceptChanges method which commits all the changes made to the dataset since last time Acceptchanges was performed.
Q76. Is there a way to suppress the finalize process inside the garbage collector forcibly in .NET?
Ans. Use the GC.SuppressFinalize() method.
Q77. What is the use of the dispose() method in .NET?
Ans. The Dispose method in .NET belongs to IDisposable interface and it is best used to release unmanaged objects like File objects, Windows API objects, Database connection objects, COM objects etc from the memory. Its performance is better than the finalize() method.
Q78. Is it possible to have have different access modifiers on the get and set methods of a property in .NET?
Ans. No we can not have different modifiers of a common property, which means that if the access modifier of a property's get method is protected, and it must be protected for the set method as well.
Q79. In .NET, is it possible for two catch blocks to be executed in one go?
Ans. This is NOT possible because once the correct catch block is executed then the code flow goes to the finally block.
Q80. Is there any difference between System.String and System.StringBuilder classes?
Ans. System.String is immutable by nature whereas System.StringBuilder can have a mutable string in which plenty of processes may be performed.
Short Answer .NET Interview Questions (PAGE 5)
Q81. What technique is used to figure out that the page request is a postback?
Ans. The IsPostBack property of the page object may be used to check whether the page request is a postback or not. IsPostBack property is of the type Boolean.
Q82. Which event of the ASP.NET page life cycle completely loads all the controls on the web page?
Ans. The Page_load event of the ASP.NET page life cycle assures that all controls are completely loaded. Even though the controls are also accessible in Page_Init event but here, the viewstate is incomplete.
Q83. How is ViewState information persisted across postbacks in an ASP.NET webpage?
Ans. Using HTML Hidden Fields, ASP.NET creates a hidden field with an ID="__VIEWSTATE" and the value of the page's viewstate is encoded (hashed) for security.
Q84. What is the ValidationSummary control in ASP.NET used for?
Ans. The ValidationSummary control in ASP.NET displays summary of all the current validation errors.
Q85. What is AutoPostBack feature in ASP.NET?
Ans. In case it is required for a server side control to postback when any of its event is triggered, then the AutoPostBack property of this control is set to true.
Q86. What is the difference between Web.config and Machine.Config in .NET?
Ans. Web.config file is used to make the settings to a web application, whereas Machine.config file is used to make settings to all ASP.NET applications on a server(the server machine).
Q87. What is the difference between a session object and an application object?
Ans. A session object can persist information between HTTP requests for a particular user, whereas an application object can be used globally for all the users.
Q88. Which control has a faster performance, Repeater or Datalist?
Ans. Repeater.
Q89. Which control has a faster performance, Datagrid or Datalist?
Ans. Datalist.
Q90. How to we add customized columns in a Gridview in ASP.NET?
Ans. Make use of the TemplateField column.
Q91. Is it possible to stop the clientside validation of an entire page?
Ans. Set Page.Validate = false;
Q92. Is it possible to disable client side script in validators?
Ans. Yes. simply EnableClientScript = false.
Q93. How do we enable tracing in .NET applications?
Ans. <%@ Page Trace="true" %>
Q94. How to kill a user session in ASP.NET?
Ans. Use the Session.abandon() method.
Q95. Is it possible to perform forms authentication with cookies disabled on a browser?
Ans. No, it is not possible.
Q96. What are the steps to use a checkbox in a gridview?
Ans.
Q97. What are design patterns in .NET?
Ans. A Design pattern is a repeatitive solution to a repeatitive problem in the design of a software architecture.
Q98. What is difference between dataset and datareader in ADO.NET?
Ans. A DataReader provides a forward-only and read-only access to data, while the DataSet object can carry more than one table and at the same time hold the relationships between the tables. Also note that a DataReader is used in a connected architecture whereas a Dataset is used in a disconnected architecture.
Q99. Can connection strings be stored in web.config?
Ans. Yes, in fact this is the best place to store the connection string information.
Q100. Whats the difference between web.config and app.config?
Ans. Web.config is used for web based asp.net applications whereas app.config is used for windows based applications.
Polymorphism means allowing a single definition to be used with different types of data (specifically, different classes of objects). For example, a polymorphic function definition can replace several type-specific ones, and a single polymorphic operator can act in expressions of various types. Many programming languages implement some forms of polymorphism.
The concept of polymorphism applies to data types in addition to functions. A function that can evaluate to and be applied to values of different types is known as a polymorphic function. A data type that contains elements of different types is known as a polymorphic data type.
Polymorphism may be achieved by overloading a function, overloading an operator, changing the order of types, changing the types using the same name for the member in context.
Example:
Public Class Calc
{
public void fnMultiply(int x, int y)
{ return x * y; }
public void fnMultiply(int x, int y, int z)
{ return x * y * z; }
}
...
...
Calc obj;
int Result;
Result = obj.fnMultiply(2,3,4); // The second fnMultiply would be called
Result = obj.fnMultiply(3,4); // The first fnMultiply would be called
//Here, the call depends on the number of parameters passed, polymorphism is achieved using overloading
Short Answer .NET Interview Questions (PAGE 1)
Q1. Explain the differences between Server-side and Client-side code?
Ans. Server side code will execute at server (where the website is hosted) end, & all the business logic will execute at server end where as client side code will execute at client side (usually written in javascript, vbscript, jscript) at browser end.
Q2. What type of code (server or client) is found in a Code-Behind class?
Ans. Server side code.
Q3. How to make sure that value is entered in an asp:Textbox control?
Ans. Use a RequiredFieldValidator control.
Q4. Which property of a validation control is used to associate it with a server control on that page?
Ans. ControlToValidate property.
Q5. How would you implement inheritance using VB.NET & C#?
Ans. C# Derived Class : Baseclass
VB.NEt : Derived Class Inherits Baseclass
Q6. Which method is invoked on the DataAdapter control to load the generated dataset with data?
Ans. Fill() method.
Q7. What method is used to explicitly kill a user's session?
Ans. Session.Abandon()
Q8. What property within the asp:gridview control is changed to bind columns manually?
Ans. Autogenerated columns is set to false
Q9. Which method is used to redirect the user to another page without performing a round trip to the client?
Ans. Server.Transfer method.
Q10. How do we use different versions of private assemblies in same application without re-build?
Ans.Inside the Assemblyinfo.cs or Assemblyinfo.vb file, we need to specify assembly version.
assembly: AssemblyVersion
Q11. Is it possible to debug java-script in .NET IDE? If yes, how?
Ans. Yes, simply write "debugger" statement at the point where the breakpoint needs to be set within the javascript code and also enable javascript debugging in the browser property settings.
Q12. How many ways can we maintain the state of a page?
Ans. 1. Client Side - Query string, hidden variables, viewstate, cookies
2. Server side - application , cache, context, session, database
Q13. What is the use of a multicast delegate?
Ans. A multicast delegate may be used to call more than one method.
Q14. What is the use of a private constructor?
Ans. A private constructor may be used to prevent the creation of an instance for a class.
Q15. What is the use of Singleton pattern?
Ans. A Singleton pattern .is used to make sure that only one instance of a class exists.
Q16. When do we use a DOM parser and when do we use a SAX parser?
Ans. The DOM Approach is useful for small documents in which the program needs to process a large portion of the document whereas the SAX approach is useful for large documents in which the program only needs to process a small portion of the document.
Q17. Will the finally block be executed if an exception has not occurred?
Ans.Yes it will execute.
Q18. What is a Dataset?
Ans. A dataset is an in memory database kindof object that can hold database information in a disconnected environment.
Q19. Is XML a case-sensitive markup language?
Ans. Yes.
Q20. What is an .ashx file?
Ans. It is a web handler file that produces output to be consumed by an xml consumer client (rather than a browser).
Short Answer .NET Interview Questions (PAGE 2)
Q21. What is encapsulation?
Ans. Encapsulation is the OOPs concept of binding the attributes and behaviors in a class, hiding the implementation of the class and exposing the functionality.
Q22. What is Overloading?
Ans. When we add a new method with the same name in a same/derived class but with different number/types of parameters, the concept is called overluoad and this ultimately implements Polymorphism.
Q23. What is Overriding?
Ans. When we need to provide different implementation in a child class than the one provided by base class, we define the same method with same signatures in the child class and this is called overriding.
Q24. What is a Delegate?
Ans. A delegate is a strongly typed function pointer object that encapsulates a reference to a method, and so the function that needs to be invoked may be called at runtime.
Q25. Is String a Reference Type or Value Type in .NET?
Ans. String is a Reference Type object.
Q26. What is a Satellite Assembly?
Ans. Satellite assemblies contain resource files corresponding to a locale (Culture + Language) and these assemblies are used in deploying an application globally for different languages.
Q27. What are the different types of assemblies and what is their use?
Ans. Private, Public(also called shared) and Satellite Assemblies.
Q28. Are MSIL and CIL the same thing?
Ans. Yes, CIL is the new name for MSIL.
Q29. What is the base class of all web forms?
Ans. System.Web.UI.Page
Q30. How to add a client side event to a server control?
Ans. Example... BtnSubmit.Attributes.Add("onclick","javascript:fnSomeFunctionInJavascript()");
Q31. How to register a client side script from code-behind?
Ans. Use the Page.RegisterClientScriptBlock method in the server side code to register the script that may be built using a StringBuilder.
Q32. Can a single .NET DLL contain multiple classes?
Ans. Yes, a single .NET DLL may contain any number of classes within it.
Q33. What is DLL Hell?
Ans. DLL Hell is the name given to the problem of old unmanaged DLL's due to which there was a possibility of version conflict among the DLLs.
Q34. can we put a break statement in a finally block?
Ans. The finally block cannot have the break, continue, return and goto statements.
Q35. What is a CompositeControl in .NET?
Ans. CompositeControl is an abstract class in .NET that is inherited by those web controls that contain child controls within them.
Q36. Which control in asp.net is used to display data from an xml file and then displayed using XSLT?
Ans. Use the asp:Xml control and set its DocumentSource property for associating an xml file, and set its TransformSource property to set the xml control's xsl file for the XSLT transformation.
Q37. Can we run ASP.NET 1.1 application and ASP.NET 2.0 application on the same computer?
Ans. Yes, though changes in the IIS in the properties for the site have to be made during deployment of each.
Q38. What are the new features in .NET 2.0?
Ans. Plenty of new controls, Generics, anonymous methods, partial classes, iterators, property visibility (separate visibility for get and set) and static classes.
Q39. Can we pop a MessageBox in a web application?
Ans. Yes, though this is done clientside using an alert, prompt or confirm or by opening a new web page that looks like a messagebox.
Q40. What is managed data?
Ans. The data for which the memory management is taken care by .Net runtime’s garbage collector, and this includes tasks for allocation de-allocation.
Short Answer .NET Interview Questions (PAGE 3)
Q41. How to instruct the garbage collector to collect unreferenced data?
Ans. We may call the garbage collector to collect unreferenced data by executing the System.GC.Collect() method.
Q42. How can we set the Focus on a control in ASP.NET?
Ans. txtBox123.Focus(); OR Page.SetFocus(NameOfControl);
Q43. What are Partial Classes in Asp.Net 2.0?
Ans. In .NET 2.0, a class definition may be split into multiple physical files but partial classes do not make any difference to the compiler as during compile time, the compiler groups all the partial classes and treats them as a single class.
Q44. How to set the default button on a Web Form?
Ans.
Q45.Can we force the garbage collector to run?
Ans. Yes, using the System.GC.Collect(), the garbage collector is forced to run in case required to do so.
Q46. What is Boxing and Unboxing?
Ans. Boxing is the process where any value type can be implicitly converted to a reference type object while Unboxing is the opposite of boxing process where the reference type is converted to a value type.
Q47. What is Code Access security? What is CAS in .NET?
Ans. CAS is the feature of the .NET security model that determines whether an application or a piece of code is permitted to run and decide the resources it can use while running.
Q48. What is Multi-tasking?
Ans. It is a feature of operating systems through which multiple programs may run on the operating system at the same time, just like a scenario where a Notepad, a Calculator and the Control Panel are open at the same time.
Q49. What is Multi-threading?
Ans. When an application performs different tasks at the same time, the application is said to exhibit multithreading as several threads of a process are running.2
Q50. What is a Thread?
Ans. A thread is an activity started by a process and its the basic unit to which an operating system allocates processor resources.
Q51. What does AddressOf in VB.NET operator do?
Ans. The AddressOf operator is used in VB.NET to create a delegate object to a method in order to point to it.
Q52. How to refer to the current thread of a method in .NET?
Ans. In order to refer to the current thread in .NET, the Thread.CurrentThread method can be used. It is a public static property.
Q53. How to pause the execution of a thread in .NET?
Ans. The thread execution can be paused by invoking the Thread.Sleep(IntegerValue) method where IntegerValue is an integer that determines the milliseconds time frame for which the thread in context has to sleep.
Q54. How can we force a thread to sleep for an infinite period?
Ans. Call the Thread.Interupt() method.
Q55. What is Suspend and Resume in .NET Threading?
Ans. Just like a song may be paused and played using a music player, a thread may be paused using Thread.Suspend method and may be started again using the Thread.Resume method. Note that sleep method immediately forces the thread to sleep whereas the suspend method waits for the thread to be in a persistable position before pausing its activity.
Q56. How can we prevent a deadlock in .Net threading?
Ans. Using methods like Monitoring, Interlocked classes, Wait handles, Event raising from between threads, using the ThreadState property.
Q57. What is Ajax?
Ans. Asyncronous Javascript and XML - Ajax is a combination of client side technologies that sets up asynchronous communication between the user interface and the web server so that partial page rendering occur instead of complete page postbacks.
Q58. What is XmlHttpRequest in Ajax?
Ans. It is an object in Javascript that allows the browser to communicate to a web server asynchronously without making a postback.
Q59. What are the different modes of storing an ASP.NET session?
Ans. InProc (the session state is stored in the memory space of the Aspnet_wp.exe process but the session information is lost when IIS reboots), StateServer (the Session state is serialized and stored in a separate process call Viewstate is an object in .NET that automatically persists control setting values across the multiple requests for the same page and it is internally maintained as a hidden field on the web page though its hashed for security reasons.
Q60. What is a delegate in .NET?
Ans. A delegate in .NET is a class that can have a reference to a method, and this class has a signature that can refer only those methods that have a signature which complies with the class.
Short Answer .NET Interview Questions (PAGE 4)
Q61. Is a delegate a type-safe functions pointer?
Ans. Yes
Q62. What is the return type of an event in .NET?
Ans. There is No return type of an event in .NET.
Q63. Is it possible to specify an access specifier to an event in .NET?
Ans. Yes, though they are public by default.
Q64. Is it possible to create a shared event in .NET?
Ans. Yes, but shared events may only be raised by shared methods.
Q65. How to prevent overriding of a class in .NET?
Ans. Use the keyword NotOverridable in VB.NET and sealed in C#.
Q66. How to prevent inheritance of a class in .NET?
Ans. Use the keyword NotInheritable in VB.NET and sealed in C#.
Q67. What is the purpose of the MustInherit keyword in VB.NET?
Ans. MustInherit keyword in VB.NET is used to create an abstract class.
Q68. What is the access modifier of a member function of in an Interface created in .NET?
Ans. It is always public, we cant use any other modifier other than the public modifier for the member functions of an Interface.
Q69. What does the virtual keyword in C# mean?
Ans. The virtual keyword signifies that the method and property may be overridden.
Q70. How to create a new unique ID for a control?
Ans. ControlName.ID = "ControlName" + Guid.NewGuid().ToString(); //Make use of the Guid class
Q71A. What is a HashTable in .NET?
Ans. A Hashtable is an object that implements the IDictionary interface, and can be used to store key value pairs. The key may be used as the index to access the values for that index.
Q71B. What is an ArrayList in .NET?
Ans. Arraylist object is used to store a list of values in the form of a list, such that the size of the arraylist can be increased and decreased dynamically, and moreover, it may hold items of different types. Items in an arraylist may be accessed using an index.
Q72. What is the value of the first item in an Enum? 0 or 1?
Ans. 0
Q73. Can we achieve operator overloading in VB.NET?
Ans. Yes, it is supported in the .NET 2.0 version, the "operator" keyword is used.
Q74. What is the use of Finalize method in .NET?
Ans. .NET Garbage collector performs all the clean up activity of the managed objects, and so the finalize method is usually used to free up the unmanaged objects like File objects, Windows API objects, Database connection objects, COM objects etc.
Q75. How do you save all the data in a dataset in .NET?
Ans. Use the AcceptChanges method which commits all the changes made to the dataset since last time Acceptchanges was performed.
Q76. Is there a way to suppress the finalize process inside the garbage collector forcibly in .NET?
Ans. Use the GC.SuppressFinalize() method.
Q77. What is the use of the dispose() method in .NET?
Ans. The Dispose method in .NET belongs to IDisposable interface and it is best used to release unmanaged objects like File objects, Windows API objects, Database connection objects, COM objects etc from the memory. Its performance is better than the finalize() method.
Q78. Is it possible to have have different access modifiers on the get and set methods of a property in .NET?
Ans. No we can not have different modifiers of a common property, which means that if the access modifier of a property's get method is protected, and it must be protected for the set method as well.
Q79. In .NET, is it possible for two catch blocks to be executed in one go?
Ans. This is NOT possible because once the correct catch block is executed then the code flow goes to the finally block.
Q80. Is there any difference between System.String and System.StringBuilder classes?
Ans. System.String is immutable by nature whereas System.StringBuilder can have a mutable string in which plenty of processes may be performed.
Short Answer .NET Interview Questions (PAGE 5)
Q81. What technique is used to figure out that the page request is a postback?
Ans. The IsPostBack property of the page object may be used to check whether the page request is a postback or not. IsPostBack property is of the type Boolean.
Q82. Which event of the ASP.NET page life cycle completely loads all the controls on the web page?
Ans. The Page_load event of the ASP.NET page life cycle assures that all controls are completely loaded. Even though the controls are also accessible in Page_Init event but here, the viewstate is incomplete.
Q83. How is ViewState information persisted across postbacks in an ASP.NET webpage?
Ans. Using HTML Hidden Fields, ASP.NET creates a hidden field with an ID="__VIEWSTATE" and the value of the page's viewstate is encoded (hashed) for security.
Q84. What is the ValidationSummary control in ASP.NET used for?
Ans. The ValidationSummary control in ASP.NET displays summary of all the current validation errors.
Q85. What is AutoPostBack feature in ASP.NET?
Ans. In case it is required for a server side control to postback when any of its event is triggered, then the AutoPostBack property of this control is set to true.
Q86. What is the difference between Web.config and Machine.Config in .NET?
Ans. Web.config file is used to make the settings to a web application, whereas Machine.config file is used to make settings to all ASP.NET applications on a server(the server machine).
Q87. What is the difference between a session object and an application object?
Ans. A session object can persist information between HTTP requests for a particular user, whereas an application object can be used globally for all the users.
Q88. Which control has a faster performance, Repeater or Datalist?
Ans. Repeater.
Q89. Which control has a faster performance, Datagrid or Datalist?
Ans. Datalist.
Q90. How to we add customized columns in a Gridview in ASP.NET?
Ans. Make use of the TemplateField column.
Q91. Is it possible to stop the clientside validation of an entire page?
Ans. Set Page.Validate = false;
Q92. Is it possible to disable client side script in validators?
Ans. Yes. simply EnableClientScript = false.
Q93. How do we enable tracing in .NET applications?
Ans. <%@ Page Trace="true" %>
Q94. How to kill a user session in ASP.NET?
Ans. Use the Session.abandon() method.
Q95. Is it possible to perform forms authentication with cookies disabled on a browser?
Ans. No, it is not possible.
Q96. What are the steps to use a checkbox in a gridview?
Ans.
Q97. What are design patterns in .NET?
Ans. A Design pattern is a repeatitive solution to a repeatitive problem in the design of a software architecture.
Q98. What is difference between dataset and datareader in ADO.NET?
Ans. A DataReader provides a forward-only and read-only access to data, while the DataSet object can carry more than one table and at the same time hold the relationships between the tables. Also note that a DataReader is used in a connected architecture whereas a Dataset is used in a disconnected architecture.
Q99. Can connection strings be stored in web.config?
Ans. Yes, in fact this is the best place to store the connection string information.
Q100. Whats the difference between web.config and app.config?
Ans. Web.config is used for web based asp.net applications whereas app.config is used for windows based applications.
OOP concept Interview Questions
1. Describe OOPs concepts.The four main concepts are involved in OOP:
Abstraction
Encapsulation
Inheritance
Polymorphism
Abstraction is hiding of information from others. In case of Java, its hiding implementation of a method/ object. For example if an interface is available to outer world, so end user won’t know about implementing class details. This is just a kind of abstraction. Abstraction could be anywhere in java, wherever we hide some information, we call it abstraction.
Encapsulation is combining data and method along with implementation hiding within the class. Implementation hiding is done with the help of access modifiers (public, protected, package, private).
Inheritance is the capability of a class to use the properties and methods of another class while adding its own functionality. Although inheritance may sometimes imply (especially in Java, where the keyword for inheritance is extends) that you are going to add new methods to the interface, that’s not necessarily true. The second and more important way to differentiate your new class is to change the behavior of an existing base-class method. This is referred to as overriding that method.
Polymorphism is something like one name many forms. Polymorphism is also known as dynamic binding or late binding or run-time binding.
2. What is Polymorphism? The meaning of Polymorphism is something like one name many forms. Polymorphism is also known as dynamic binding or late binding or run-time binding.Method overloading: Method overloading can be done on the basis of number of argument in a method , or order of arguments or class of the function. Overloading can’t be done on the basis of return type. This is because sometime methods are called only for their side effect and their return value might be ignored.
3. What is an abstract class? You create an abstract class when you want to manipulate a set of classes through this common interface. All derived-class methods that match the signature of the base-class declaration will be called using the dynamic binding mechanism.A class containing abstract methods is called an abstract class. Class does not contain implementation for Abstract methods. If a class contains one or more abstract methods, the class itself must be qualified as abstract. (Otherwise, the compiler gives you an error message.
4. What is an interface?The interface keyword takes the abstract concept one step further. You could think of it as a “pure” abstract class. It allows the creator to establish the form for a class: method names, argument lists, and return types, but no method bodies. An interface can also contain fields, but these are implicitly static and final. An interface provides only a form, but no implementation. An interface says, “This is what all classes that implement this particular interface will look like.”
Abstraction
Encapsulation
Inheritance
Polymorphism
Abstraction is hiding of information from others. In case of Java, its hiding implementation of a method/ object. For example if an interface is available to outer world, so end user won’t know about implementing class details. This is just a kind of abstraction. Abstraction could be anywhere in java, wherever we hide some information, we call it abstraction.
Encapsulation is combining data and method along with implementation hiding within the class. Implementation hiding is done with the help of access modifiers (public, protected, package, private).
Inheritance is the capability of a class to use the properties and methods of another class while adding its own functionality. Although inheritance may sometimes imply (especially in Java, where the keyword for inheritance is extends) that you are going to add new methods to the interface, that’s not necessarily true. The second and more important way to differentiate your new class is to change the behavior of an existing base-class method. This is referred to as overriding that method.
Polymorphism is something like one name many forms. Polymorphism is also known as dynamic binding or late binding or run-time binding.
2. What is Polymorphism? The meaning of Polymorphism is something like one name many forms. Polymorphism is also known as dynamic binding or late binding or run-time binding.Method overloading: Method overloading can be done on the basis of number of argument in a method , or order of arguments or class of the function. Overloading can’t be done on the basis of return type. This is because sometime methods are called only for their side effect and their return value might be ignored.
3. What is an abstract class? You create an abstract class when you want to manipulate a set of classes through this common interface. All derived-class methods that match the signature of the base-class declaration will be called using the dynamic binding mechanism.A class containing abstract methods is called an abstract class. Class does not contain implementation for Abstract methods. If a class contains one or more abstract methods, the class itself must be qualified as abstract. (Otherwise, the compiler gives you an error message.
4. What is an interface?The interface keyword takes the abstract concept one step further. You could think of it as a “pure” abstract class. It allows the creator to establish the form for a class: method names, argument lists, and return types, but no method bodies. An interface can also contain fields, but these are implicitly static and final. An interface provides only a form, but no implementation. An interface says, “This is what all classes that implement this particular interface will look like.”
Basic .Net Question
1. What is Assembly name and name space?
An assembly is a logical unit of code. Physically it may exist as .dll or an exe, which can contain one or more files and they can be any file types like image files, text files etc. along with DLLs or EXEs. When you compile your source code by default the exe/dll which is generated is actually an assembly and every assembly file contains information about itself which is called as Assembly Manifest. Namespace is an abstract container providing context for the items it holds and allows disambiguation of items having the same name (residing in different namespaces. It can also be said as a context for identifiers. So under a namespace you can have multiple assemblies.
2. what is capacity of dataset?
ans: DataSet is logical represantation of database so it can store as much as database.
3. What is deployment? How do you deploy .Net and Java applications
ans: Deployment - It is the procedure to deploy Web Application on the Server. You can deploy .Net application by simply Xcopy and create virtual directory for the application on server.
4. Where this DataSet is Stored?
ans: Dataset is an in-memory representation of a database. Its stored no where but in memory. Goes off when GC stats after a littl sleep.
5. How different are interface and abstract class in .Net?
ans: When a class is not provided with full functionalitythen it is declared as abstract.it doesn't support instance creation as well as it cannot be overridable to child class.interface is a colection of methods only without functionality.interface is 90% same as abstract class.
6. Can you explain the difference between an ADO.NET Dataset and an ADO Recordset?
ans: A DataSet can represent an entire relational database in memory, complete with tables, relations, and views.
A DataSet is designed to work without any continuing connection to the original data source.
Data in a DataSet is bulk-loaded, rather than being loaded on demand.
There's no concept of cursor types in a DataSet.
DataSets have no current record pointer You can use For Each loops to move through the data.
You can store many edits in a DataSet, and write them to the original data source in a single operation.
Though the DataSet is universal, other objects in ADO.NET come in different versions for different data sources.
7.What is ADO.NET?
ans: ADO.NET is a set of classes that expose data access services to the .NET Applications. ADO ( or ActiveX Data Objects ) is an easy-to-use yet extensible technology for adding database connectivity to Web pages. ADO.NET is the next generation of ADO, providing the interface for accessing, manipulating, and exchanging data in the Microsoft .NET Framework.
The ADO.NET components have been designed to factor data access from data manipulation. There are two central components of ADO.NET that accomplish this: the DataSet, and the .NET Framework data provider, which is a set of components including the Connection, Command, DataReader, and DataAdapter objects.
8.What is DataSet?
ans: A DataSet is a cache of records retrieved from a data source. It works like a virtual data store: A dataset includes one or more tables based on the tables in the actual database, and it can include information about the relationships between those tables and constraints on what data the tables can contain.
The DataSet object is central to supporting disconnected, distributed data scenarios with ADO.NET. The DataSet class is explicitly designed for data access independent of any data source. As a result it can be used with multiple and differing data sources, used with XML data, or used to manage data local to the application. The DataSet contains a collection of one or more DataTable objects made up of rows and columns of data, as well as primary key, foreign key, constraint, and relation information about the data in the DataTable objects.
9.Explain How ADO.NET Works?
ans: ADO.NET uses two types of objects to access the data in a database: datasets, which can contain one or more data tables, and .NET data provider objects, which include data adapters, commands, and connections. A dataset stores data from the database so that it can be accessed by the application. The .NET data provider objects retrieve data from and update data in the database.
To retrieve data from a database and store it in a data table, a data adapter object issues a Select statement that stored in a command object. Next, the command object uses a connection object to connect to the database and retrieve the data. Then, the data is passed back to the data adapter, which stores the data in the dataset. To update the data in a database based on the data in a data table, the data adapter object issues an Insert, Update, or Delete statement thats stored in a command object. Then, the command object uses a connection to connect to the database and update the data.
10.What are the main classes/Components of ADO.NET?
ans: ADO.NET is comprised of many classes, but five take center stage: Connection Represents a connection to a data source. Command Represents a query or a command that is to be executed by a data source.
DataSet Represents data. The DataSet can be filled either from a data source (using a DataAdapter object) or dynamically. DataAdapter Used for filling a DataSet from a data source. DataReader Used for fast, efficient, forward-only reading of a data source.
11.Explain the Use of connection pooling in ADO.NET
ans: Connection pooling enables an application to use a connection from a pool of connections that do not need to be re-established for each use. Once a connection has been created and placed in a connection pool, an application can reuse that connection without performing the complete connection creation process. By default, the connection pool is created when the first connection with a unique connection string connects to the database. The pool is populated with connections up to the minimum pool size. Additional connections can be added until the pool reaches the maximum pool size.
When a user request a connection, it is returned from the pool rather than establishing new connection and, when a user releases a connection, it is returned to the pool rather than being released. But be sure than your connections use the same connection string each time. Here is the Syntax conn.ConnectionString = "integrated Security=SSPI; SERVER=192.168.0.123; DATABASE=MY_DB; Min Pool Size=4;Max Pool Size=40;Connect Timeout=14;";
12.How can you search the Data in DataSet?
ans: Searching for Data in the DataSetWhen querying a DataSet for rows that match particular criteria, you can increase the performance of your searches by taking advantage of index-based lookups. When you assign a PrimaryKey value to a DataTable, an index is created. When you create a DataView for a DataTable, an index is also created. Here are a few tips for taking advantage of index-based lookups.
13.How can you update Database using DataAdapter and the DataSet?
ans: Updating the Database with a DataAdapter and the DataSet The Update method of the DataAdapter is called to resolve changes from a DataSet back to the data source. The Update method, like the Fill method, takes as arguments an instance of a DataSet, and an optional DataTable object or DataTable name. The DataSet instance is the DataSet that contains the changes that have been made, and the DataTable identifies the table from which to retrieve the changes.
When you call the Update method, the DataAdapter analyzes the changes that have been made and executes the appropriate command (INSERT, UPDATE, or DELETE). When the DataAdapter encounters a change to a DataRow, it uses the InsertCommand, UpdateCommand, or DeleteCommand to process the change.
An assembly is a logical unit of code. Physically it may exist as .dll or an exe, which can contain one or more files and they can be any file types like image files, text files etc. along with DLLs or EXEs. When you compile your source code by default the exe/dll which is generated is actually an assembly and every assembly file contains information about itself which is called as Assembly Manifest. Namespace is an abstract container providing context for the items it holds and allows disambiguation of items having the same name (residing in different namespaces. It can also be said as a context for identifiers. So under a namespace you can have multiple assemblies.
2. what is capacity of dataset?
ans: DataSet is logical represantation of database so it can store as much as database.
3. What is deployment? How do you deploy .Net and Java applications
ans: Deployment - It is the procedure to deploy Web Application on the Server. You can deploy .Net application by simply Xcopy and create virtual directory for the application on server.
4. Where this DataSet is Stored?
ans: Dataset is an in-memory representation of a database. Its stored no where but in memory. Goes off when GC stats after a littl sleep.
5. How different are interface and abstract class in .Net?
ans: When a class is not provided with full functionalitythen it is declared as abstract.it doesn't support instance creation as well as it cannot be overridable to child class.interface is a colection of methods only without functionality.interface is 90% same as abstract class.
6. Can you explain the difference between an ADO.NET Dataset and an ADO Recordset?
ans: A DataSet can represent an entire relational database in memory, complete with tables, relations, and views.
A DataSet is designed to work without any continuing connection to the original data source.
Data in a DataSet is bulk-loaded, rather than being loaded on demand.
There's no concept of cursor types in a DataSet.
DataSets have no current record pointer You can use For Each loops to move through the data.
You can store many edits in a DataSet, and write them to the original data source in a single operation.
Though the DataSet is universal, other objects in ADO.NET come in different versions for different data sources.
7.What is ADO.NET?
ans: ADO.NET is a set of classes that expose data access services to the .NET Applications. ADO ( or ActiveX Data Objects ) is an easy-to-use yet extensible technology for adding database connectivity to Web pages. ADO.NET is the next generation of ADO, providing the interface for accessing, manipulating, and exchanging data in the Microsoft .NET Framework.
The ADO.NET components have been designed to factor data access from data manipulation. There are two central components of ADO.NET that accomplish this: the DataSet, and the .NET Framework data provider, which is a set of components including the Connection, Command, DataReader, and DataAdapter objects.
8.What is DataSet?
ans: A DataSet is a cache of records retrieved from a data source. It works like a virtual data store: A dataset includes one or more tables based on the tables in the actual database, and it can include information about the relationships between those tables and constraints on what data the tables can contain.
The DataSet object is central to supporting disconnected, distributed data scenarios with ADO.NET. The DataSet class is explicitly designed for data access independent of any data source. As a result it can be used with multiple and differing data sources, used with XML data, or used to manage data local to the application. The DataSet contains a collection of one or more DataTable objects made up of rows and columns of data, as well as primary key, foreign key, constraint, and relation information about the data in the DataTable objects.
9.Explain How ADO.NET Works?
ans: ADO.NET uses two types of objects to access the data in a database: datasets, which can contain one or more data tables, and .NET data provider objects, which include data adapters, commands, and connections. A dataset stores data from the database so that it can be accessed by the application. The .NET data provider objects retrieve data from and update data in the database.
To retrieve data from a database and store it in a data table, a data adapter object issues a Select statement that stored in a command object. Next, the command object uses a connection object to connect to the database and retrieve the data. Then, the data is passed back to the data adapter, which stores the data in the dataset. To update the data in a database based on the data in a data table, the data adapter object issues an Insert, Update, or Delete statement thats stored in a command object. Then, the command object uses a connection to connect to the database and update the data.
10.What are the main classes/Components of ADO.NET?
ans: ADO.NET is comprised of many classes, but five take center stage: Connection Represents a connection to a data source. Command Represents a query or a command that is to be executed by a data source.
DataSet Represents data. The DataSet can be filled either from a data source (using a DataAdapter object) or dynamically. DataAdapter Used for filling a DataSet from a data source. DataReader Used for fast, efficient, forward-only reading of a data source.
11.Explain the Use of connection pooling in ADO.NET
ans: Connection pooling enables an application to use a connection from a pool of connections that do not need to be re-established for each use. Once a connection has been created and placed in a connection pool, an application can reuse that connection without performing the complete connection creation process. By default, the connection pool is created when the first connection with a unique connection string connects to the database. The pool is populated with connections up to the minimum pool size. Additional connections can be added until the pool reaches the maximum pool size.
When a user request a connection, it is returned from the pool rather than establishing new connection and, when a user releases a connection, it is returned to the pool rather than being released. But be sure than your connections use the same connection string each time. Here is the Syntax conn.ConnectionString = "integrated Security=SSPI; SERVER=192.168.0.123; DATABASE=MY_DB; Min Pool Size=4;Max Pool Size=40;Connect Timeout=14;";
12.How can you search the Data in DataSet?
ans: Searching for Data in the DataSetWhen querying a DataSet for rows that match particular criteria, you can increase the performance of your searches by taking advantage of index-based lookups. When you assign a PrimaryKey value to a DataTable, an index is created. When you create a DataView for a DataTable, an index is also created. Here are a few tips for taking advantage of index-based lookups.
13.How can you update Database using DataAdapter and the DataSet?
ans: Updating the Database with a DataAdapter and the DataSet The Update method of the DataAdapter is called to resolve changes from a DataSet back to the data source. The Update method, like the Fill method, takes as arguments an instance of a DataSet, and an optional DataTable object or DataTable name. The DataSet instance is the DataSet that contains the changes that have been made, and the DataTable identifies the table from which to retrieve the changes.
When you call the Update method, the DataAdapter analyzes the changes that have been made and executes the appropriate command (INSERT, UPDATE, or DELETE). When the DataAdapter encounters a change to a DataRow, it uses the InsertCommand, UpdateCommand, or DeleteCommand to process the change.
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