Which interface implements the standard query operators in LINQ?

Correct Answer: The standard query operators in LINQ are the extension methods that form the LINQ pattern These operators form an API that enables querying of any NET array or collection It operates on sequences and allows you to perform operations, such as determining if a value exists in the sequence and performing an aggregated function, such as a summation over a sequence

Correct Answer: After you add a LINQ to SQL Classes item to a project and open the O/R Designer, the empty design surface represents an empty DataContext class ready to be configured The DataContext class is a LINQ to SQL class that acts as a conduit between a SQL Server database and the LINQ to SQL entity classes mapped to that database This class contains the connection string information and the methods for connecting to a database and manipulating the data in the database It is configured with connection information provided by the first item that is dragged onto the design surface

Correct 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

Correct 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

Correct 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

Correct Answer: Windows services, previously known as NT services, are applications that are installed on the system as system services In other words, Windows services are applications that run in the background with the Windows operating system The primary use of Windows services is to reduce the consumption of memory required for performing backend operations Let's take an example to understand this easily Suppose you want to perform a variety of functions, such as monitor the performance of your computer or application, check the status of an application, and manage various devices, such as printers In such a case, you can use Windows services to reduce memory consumption In addition, Windows services can run on your system even if you have not logged on to your computer In addition, these services do not have any user interface

Correct Answer: The ServiceInstaller class, also known as the project installer class, is used to install a Windows service

Correct Answer: ASPNET AJAX, mostly called AJAX, is a set of extensions of ASPNET It is developed by Microsoft to implement AJAX functionalities in Web applications ASPNET AJAX provides a set of components that enable the developers to develop applications that can update only a specified portion of data without refreshing the entire page The ASPNET AJAX works with the AJAX Library that uses object-oriented programming (OOP) to develop rich Web applications that communicate with the server using asynchronous postback

Correct Answer: The following validation controls are available in ASPNET AJAX 40: => FilteredTextBoxExtender - Enables you to apply filtering to a text box => MaskedEditExtender and MaskedEditValidator - Restricts a user to enter only a certain pattern of characters in the TextBox by applying a mask to the input => ValidatorCalloutExtender - Attaches to the ASPNET validators so that the error messages are not displayed as a simple text but as a balloon-style ToolTip => NoBot - Prevents the spam/bot from filling the input forms automatically and uses the Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA), which is a type of challenge-response test to ensure that the response is not generated by the computer => PasswordStrengthExtender - Measures the strength of the password text entered within the text box by validating with the different strength specified parameters

Correct Answer: You should not use AJAX if: => You want the page to show in a search engine, such as Google, because WebCrawler does not execute JavaScript code => The browser does not support JavaScript => You want to create a secure application