Question 1

What is the syntax to inherit from a class in C#?

Accepted Answer

When a class is derived from another class, then the members of the base class become the members of the derived class The access modifier used while accessing members of the base class specifies the access status of the base class members inside the derived class The syntax to inherit a class from another class in C# is as follows: class MyNewClass : MyBaseclass

Question 2

How can you prevent a class from overriding in C# and Visual Basic?

Accepted Answer

You can prevent a class from overriding in C# by using the sealed keyword; whereas, the NotInheritable keyword is used to prevent a class from overriding in Visual Basic

Question 3

Explain ADO.NET in brief.

Accepted Answer

ADONET is a very important feature of NET Framework, which is used to work with data that is stored in structured data sources, such as databases and XML files The following are some of the important features of ADONET: => Contains a number of classes that provide you with various methods and attributes to manage the communication between your application and data source => Enables you to access different data sources, such as Microsoft SQL Server, and XML, as per your requirements => Provides a rich set of features, such as connection and commands that can be used to develop robust and highly efficient data services in NET applications => Provides various data providers that are specific to databases produced by various vendors For example, ADONET has a separate provider to access data from Oracle databases; whereas, another provider is used to access data from SQL databases

Question 4

What are the usages of the Command object in ADO.NET?

Accepted Answer

The following are the usages of the Command object in AD0NET: The Command object in AD0NET executes a command against the database and retrieves a DataReader or DataSet object => It also executes the INSERT, UPDATE, or DELETE command against the database => All the command objects are derived from the DbCommand class => The command object is represented by two classes: SqlCommand and OleDbCommand => The Command object provides three methods to execute commands on the database: => The ExecuteNonQuery() method executes the commands and does not return any value => The ExecuteScalar() method returns a single value from a database query => The ExecuteReader() method returns a result set by using the DataReader object

Question 5

What are the usages of the Command object in ADO.NET?

Accepted Answer

The following are the usages of the Command object in AD0NET: The Command object in AD0NET executes a command against the database and retrieves a DataReader or DataSet object => It also executes the INSERT, UPDATE, or DELETE command against the database => All the command objects are derived from the DbCommand class => The command object is represented by two classes: SqlCommand and OleDbCommand => The Command object provides three methods to execute commands on the database: => The ExecuteNonQuery() method executes the commands and does not return any value => The ExecuteScalar() method returns a single value from a database query => The ExecuteReader() method returns a result set by using the DataReader object

Question 6

What is Dynamic Language Runtime (DLR)?

Accepted Answer

DLR is a runtime environment that allows you to integrate dynamic languages with the Common Language Runtime (CLR) by adding a set of services, such as expression trees, call site caching, and dynamic object interoperability to the CLR The SystemDynamic and SystemRuntimeCompilerServices namespaces are used to hold the classes for DLR It also provides dynamic features to statically-typed languages, such as C# and Visual Basic to enable their interoperation with dynamic languages

Question 7

What is ASP.NET?

Accepted Answer

ASPNET is a specification developed by Microsoft to create dynamic Web applications, Web sites, and Web services It is a part of NET Framework You can create ASPNET applications in most of the NET compatible languages, such as Visual Basic, C#, and J# The ASPNET compiles the Web pages and provides much better performance than scripting languages, such as VBScript The Web Forms support to create powerful forms-based Web pages You can use ASPNET Web server controls to create interactive Web applications With the help of Web server controls, you can easily create a Web application

Question 8

What is the basic difference between ASP and ASP.NET?

Accepted Answer

The basic difference between ASP and ASPNET is that ASP is interpreted; whereas, ASPNET is compiled This implies that since ASP uses VBScript; therefore, when an ASP page is executed, it is interpreted On the other hand, ASPNET uses NET languages, such as C# and VBNET, which are compiled to Microsoft Intermediate Language (MSIL)

Question 9

How can you send an email message from an ASP.NET Web page?

Accepted Answer

You can use the SystemNetMailMailMessage and the SystemNetMailSmtpMail classes to send an email in your Web pages In order to send an email through your mail server, you need to create an object of the SmtpClient class and set the server name, port, and credentials

Question 10

What is the code-behind feature in ASP.NET?

Accepted Answer

The code-behind feature of ASPNET enables you to divide an ASPNET page into two files - one consisting of the presentation data, and the second, which is also called the code-behind file, consisting of all the business logic The presentation data contains the interface elements, such as HTML controls and Web server controls, and the code-behind contains the event-handling process to handle the events that are fired by these controls The file that contains the presentation data has the aspx extension The code behind file has either the cs extension (if you are using the programming language C#) or the vb (if you are using the programming language Visual Basic NET) extension

Question 11

Explain the validation controls. How many validation controls in ASP.NET 4.0?

Accepted Answer

Validation controls are responsible to validate the data of an input control Whenever you provide any input to an application, it performs the validation and displays an error message to user, in case the validation fails ASPNET 40 contains the following six types of validation controls: => CompareValidator - Performs a comparison between the values contained in two controls => CustomValidator - Writes your own method to perform extra validation => RangeValidator- Checks value according to the range of value => RegularExpressionValidator - Ensures that input is according to the specified pattern or not => RequiredFieldValidator - Checks either a control is empty or not => ValidationSummary - Displays a summary of all validation error in a central location

Question 12

Explain the concept of states in ASP.NET.

Accepted Answer

State is quite an innovative concept in Web development because it eliminates the drawback of losing state data due to reloading of a Web page By using states in a Web application, you can preserve the state of the application either at the server or client end The state of a Web application helps you to store the runtime changes that have been made to the Web application For example, as already described earlier, a change in the data source of the Web application might be initiated by a user when he/she selects and saves some products in the shopping cart If you are not using states, these changes are discarded and are not saved You may think that the whole concept of storing states is optional However, under certain circumstances, using states with applications is imperative For example, it is necessary to store states for Web applications, such as an e-commerce shopping site or an Intranet site of a company, to keep track of the requests of the users for the items they have selected on the shopping site or the days requested for vacation on the Intranet site

Question 13

What is Windows Workflow Foundation (WF)?

Accepted Answer

Windows Workflow Foundation (WF) is a technology that was first introduced in NET Framework 30 WF consists of a programming model, a workflow runtime engine, workflow designer, a rules engine, and tools to quickly build workflow-based applications on Windows WF facilitates the separation between the business process code and the actual implementation code

Question 14

What are the different types of workflow in WF?

Accepted Answer

In WF 40, the following two types of workflows are used: Flowchart workflows - Helps you to create workflows using the common flowchart elements In WF, the Flowchart activity is generally used to implement a non-sequential workflow, and occasionally it implements sequential workflows in case the FlowDecision nodes are not used The Flowchart activity contains a collection of flow nodes, which inherit from the FlowNode class The following types of nodes or elements can be a part of a flowchart: => FlowStep - Executes activities of a flowchart in a sequence => FlowDecision - Shows the execution on the basis of a Boolean condition It is similar to the If construct => FlowSwitch - Shows the execution on the basis of an exclusive switch It is similar to the Switch construct Procedural workflows - Helps you to create workflows using basic and sequential execution standards In WF, procedural workflows use flow control constructs, such as While, Switch, ForEach, and If, to execute activities These flow control constructs are similar to those found in procedural languages Procedural workflows can also contain other flow control activities, such as Flowchart and Sequence

Question 15

Explain why workflows are based on Extensible Models.

Accepted Answer

Workflows serve the purpose of automating business processes Now, since each type of business has a wide range of problems; therefore, a workflow platform needs to be extensible WF provides you with a set of base activities, such as IfElse, Code, and Delay, to build a workflow You can extend these activities or build new activities to meet your requirements Besides activities, you can also extend services, such as tracking, management, and persistence, provided by the runtime engine

Question 16

List different ways of deployment that are supported by .NET Framework 4.0.

Accepted Answer

=> Windows Installer => ClickOnce => XCOPY => Copy Web Site => Publish Web Site tool

Question 17

How can you deploy an ASP.NET Web application?

Accepted Answer

You can deploy an ASPNET Web application using either the Windows Installer deployment or ClickOnce deployment technique

Question 18

Mention the two major categories that distinctly classify the variables of C# programs.

Accepted Answer

Variables that are defined in a C# program belong to two major categories: value type and reference type The variables that are based on value type contain a value that is either allocated on a stack or allocated in-line in a structure The variables that are based on reference types store the memory address of a variable, which in turn stores the value and are allocated on the heap The variables that are based on value types have their own copy of data and therefore operations done on one variable do not affect other variables The reference-type variables reflect the changes made in the referring variables

Question 19

What is Language Integrated Query (LINQ)?

Accepted Answer

LINQ is a programming model that is the composition of general-purpose standard query operators that allow you to work with data, regardless of the data source in any NET based programming language It is the name given to a set of technologies based on the integration of query capabilities into any NET language

Question 20

Write the basic syntax of a LINQ query in Visual Basic as well as in C#.

Accepted Answer

In Visual Basic, the basic syntax of a LINQ query starts with the From clause and ends with the Select or Group By clause In addition, you can use the Where, Order By, and Order By Descending clauses to perform additional functions, such as filtering data and generating the data in a specific order In C#, the basic syntax of a LINQ query starts with the From clause and ends with the Select or group by clause In addition, you can use the where, orderby, and Orderby descending clauses to perform additional functions, such as filtering data and generating the data in a specific order

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