Application Development & Programming Flashcards

Which design pattern ensures a class has only one instance and provides a global access point to it?

Answer: Singleton

The Singleton pattern restricts instantiation of a class to one object and provides a static method to access that instance.

In C#, what is boxing?

Answer: Converting a value type to an object reference type

Boxing is the implicit conversion of a value type (like int) to type object, which allocates heap memory for the value.

Which WCF binding is most appropriate for communication between two .NET applications on the same machine?

Answer: NetNamedPipeBinding

NetNamedPipeBinding uses named pipes for inter-process communication on the same machine, offering the best performance in that scenario.

In LINQ, what does the 'deferred execution' concept mean?

Answer: The query is executed only when results are iterated

LINQ queries with deferred execution are not evaluated until the query variable is iterated, enabling dynamic composition.

Which ASP.NET mechanism allows you to store user-specific data across multiple requests without a database?

Answer: Session State

Session State stores per-user data server-side and associates it with the user's browser session via a session ID cookie.

What is the role of the 'abstract' keyword when applied to a method in C#?

Answer: The method has no implementation and must be overridden in derived classes

An abstract method declares the signature only, with no body, and forces all non-abstract derived classes to provide an implementation.

When using SQL Server with ADO.NET, what is the main advantage of using stored procedures over inline SQL?

Answer: They prevent SQL injection and benefit from execution plan caching

Stored procedures use parameterized inputs (preventing SQL injection) and their execution plans are cached by SQL Server for reuse.