LinkedIn .NET Framework Certification Exam Answers

LinkedIn .NET Framework Exam Quiz Answers

Question 1: What is the difference between a stack and queue?

• Queues process value types by a top-down hierarchy – first in, first out (FIFO). Stacks follow this principle and insert items from the lower end while deleting ones from the top – last in, first-out (LIFO).
• Queues process value types by a top-down hierarchy-last in, first-out (LIFO). Stacks follow this principle and insert items from the lower end while deleting ones from the top-first in, first-out (FIFO).
• Stacks process value types by a top-down hierarchy – last in, first-out (LIFO). Queues follow this principle and insert items from the lower end while deleting ones from the top – first in, first-out (FIFO)
• Stacks process value types by a top-down hierarchy-first in, first out (FIFO). Queues follow this principle and insert items from the lower end while deleting ones from the top-last in, first-out (LIFO).

Question 2: Which group contains all official types of JIT compilations?

• Pre-JIT, Quick-JIT, Coll-JIT
• Before-JIT, Quick-JIT, Cool-JIT
• Pre-JIT, Quick-JIT, Normal-JIT
• Pre-JIT, Econo-JIT, Normal-JIT

Question 3: What is Kestrel?

• an iOS web server initially that was later designed to work with .NET Core
• a cross-platform web server ASP.NET Core that is included by default in ASP.NET Core project templates**
• a cross-platform, open-source web server that starts up web APIs
• a free and open-source cross-platform web server software that can communicate with IIS

Question 4: When would you use asynchronous actions?

• to release the quest thread of a I/O operation
• to capture the request thread of a I/O operation
• to avoid blocking the request thread while waits for an I/O operation
• to block the request thread if it waits for an I/O operation

Question 5: What is CoreCLR?

• CoreCLR is a component that allows the highest degree of control when coding; you can Abort (), Suspend () or Resume ().
• CoreCLR is the .NET execution engine that runs the source code. Special programs called compilers must rewrite it into MSIL.
• CoreCLR is the .NET execution engine the runs the source code. Special programs called compilers must rewrite it into IL.
• CoreCLR is the .NET execution engine in .NET Core that performs functions like garbage collection and compilation to machine code.

Question 6: When you define an abstract method, how do you use it in a derived class?

• Abstract methods cannot be used in derived classes.
• In your derived class, overload the method.
• In your derived class, override the method.
• In your derived class, declare the method as virtual.

Question 7: Which code do you use if you want to trigger a garbage collection in .NET?

• Garbage.CleanUp();
• System.GC.Clear();
• System.GC.Collect();
• Garbage.Collect();

Question 8: You want to include language elements in a program. Which design pattern best fits this objective?

• Interpreter <= correct
• Command
• Bridge
• Decorator

Question 9: What makes a strong-named assembly?

• an assembly with the version specified
• a signed assembly
• an assembly with culture information
• an assembly with the name marked as important

Question 10: What happens when you concatenate two strings?

• You cannot concatenate strings in .NET.
• The second-string object is modified so it contains the concatenated strings.
• A third string object is created containing the concatenated strings.
• The first-string object is modified so it contains the concatenated strings.

Question 11: What is a delegate?

• A delegate is an object or collection initializer that adds flexibility, readability and maintainability in C#.
• A delegate in .NET is similar to a function pointer in C or C++. Using a delegate allows the programmer to encapsulate a reference to a method inside a delegate object.
• A delegate is a collection initializer that adds flexibility, readability and maintainability in .NET.
• A delegate is an extension method. Using a delegate allows the programmer to add flexibility, readability and maintainability in .NET.

Question 12: Which is a set of features that extends the query capabilities of the .NET language syntax by adding sets of new standard query operators that allow data manipulation, regardless of the data source?

• XML
• C#
• LINQ
• XAML

Question 13: What is the single responsibility principle?

• Software entities should be open for extension, but closed for modification.
• Entities must depend on abstractions, not on concrete implementations.
• Objects in a program should be repleaceble with instances of their subtypes without altering the correctness of that programm.
• A class should have only a single responsibility – that is, only changes to one part of the software’s specification should be able to affect the specification of the class.

Question 14: When should a developer use the .NET Standard class library project type?

• when you want to increase the .NET API surface area your library can access, and allow only .NET Core apps to be compatible with your library
• when you want to increase the number of apps that are compatible with your library, and decrease the .NET API surface area your library can access
• when you want to decrease speed but have more features
• when you want to increase compilation speed and have fewer features

Question 15: What is the difference between a SDK (software development kit) and runtime in .NET Core?

• The SDK is the “virtual machine” that hosts and runs the application and abstracts all the interaction with the operating system; the runtime usually includes documentation and other help files.
• The runtime is the virtual machine that hosts and runs the application and abstracts all the interaction with the operating system; the SDK usually includes documentation and other help files.
• The runtime compiles code along with the CLR; the SDK usually includes documentation and other help files.
• The SDK compiles code along with the CLR; the runtime usually includes documentation and other help files.

Question 16: What is the Common Type System (CTS)?

• the component of CLR in which .NET Framework provides support for several languages since it contains a type system that is common with all the languages
• the component of CLI in which .NET Framework provides support for several languages since it contains a type system that is common with all the languages
• the component of CLR that allows you to map the content of a file to the logical address of an application
• the component of CLR that enables you to run multiple versions of an application or component and CLR on the same computer at the same time

Question 17: Assuming y is a value type, which is an example of boxing?

• y = (int)thisObject;
• int y = 3;
• y = (int)thisObject=;3;
• object thisObject = y;

Question 18: What is an abstract class in .NET?

• An abstract class provides a partial implementation for functionality and some abstract or virtual members that must be implemented by the inheriting entities. It can declare fields too.
• An abstract class allows developers to create new classes that reuse, extend, and modify the behavior defined in other classes.
• An abstract class is responsible for keeping track of what is actually executing and where each executing thread is.
• An abstract class declares a contract or behavior that implementing classes require. It may declare only properties, methods, and events with no access modifiers. All the declared members must be implemented.

Question 19: What is the namespace for caching information in .NET?

• System.Data. Caching;
• All.System. Caching;
• System.Runtime. Caching;
• System.Compiler. Caching;

Question 20: What is an interface in .NET?

• An interface provides a partial implementation for functionality and some abstract or virtual members that must be implemented by the inheriting entities. It can declare fields too.
• An interface is responsible for keeping track of what is actually executing and where each executing thread is.
• An interface allows developers to create new classes that reuse, extend, and modify the behavior defined in other classes.
• An interface declares a contract or behavior that implementing classes require. It may declare only properties, methods, and events with no access modifiers. All the declared members must be implemented.

Question 21: What does CAS stand for and what does it do?

• CAS stands for Code Application Secrets and it enables users to restrict, on a very granular level, what hidden code can do according to a level of trust for an application.
• CAS stands for Code Access Secrets and it enables users to restrict, on a very granular level, what hidden code can do according to a level of trust.
• CAS stands for Cognitive Access Security and it enables users to restrict security logic manipulation.
• CAS stands for Code Access Security and it enables users to restrict, on a very granular level, what managed code can do according to a level of trust.

Question 22: Which is NOT true about lambda statements?

• A statement lambda cannot return a value.
• If a statement lambda has a return value, it has to use a return statement.
• A statement lambda requires using curly braces.
• A statement lambda can have more than one statement.

Question 23: Which is NOT true about a read-only variable?

• At runtime, its value is evaluated.
• It can be either static or an instance member.
• It can be initialized at declaration only.
• It can be initialized in either the constructor or the declaration.

Question 24: What is the difference between System.String and string?

• string is used for fied-size strings in C#, while System.String is used for all the strings.
• There is no such class as System.String.
• There is none—string is an alias for System. String.
• System.String is a VB.NET data type, while string is a C# type.

Question 25: When break is used inside two nested for loops, does control come out of the inner for loop or the outer for loop?

• It breaks from only the outer loop.
• It breaks from all loops.
• It breaks from only the inner loop.
• It breaks from the outer loop after the second iteration.

Question 26: You want to separate object construction from its representation. Which design pattern best fits this objective?

• Adapter
• Bridge
• Singleton
• Builder

Question 27: You want to encapsulate a command request as an object. Which design pattern best fits this objective?

• Command
• Iterator
• Facade
• Observer

Question 28: Why would Pre-JIT be used by the .NET Framework?

• to compile only the methods that are called at runtime and store those methods in cache after execution
• to compile complete source code into native code in a single compilation cycle during deployment of the application
• to compile only the methods that are called at runtime and then store them in cache for one minute
• to compile only the methods that are called at runtime and remove them from memory after execution

Question 29: What do code contracts do?

• Code contracts are data structures that can operate on demand per requirements.
• Code contracts provide a way to specify preconditions, postconditions, and object invariants in your code.
• Code contracts contain definitions for a group of related functionalities that a class or a struct can implement.
• Code contracts contain data structures for a group of related functionalities that a class or a struct can implement.

Question 30: You must connect an app to an online identity provider using OAuth. For authentication, the app uses Web Authentication Broker object. You need to make sure the app registers with the provider. Which action do you take?

• Construct an HTTP request URI and an HTTPS request URI.
• Invoke the Get Current Application Callback Uri method and construct an HTTPS request URI.
• Invoke the Authenticate Async and GetCurrentApplicationCallbackUri methods.
• Invoke the Authenticate Async method and construct an HTTPS request URI.

Question 31: You want to create a class of which only a single instance can exist. Which design pattern best fits this objective?

• Adapter
• Singleton
• Bridge
• Decorator

Question 32: What is the dependency inversion principle?

• Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.
• A class should have only a single responsibility—that is, only changes to one part of the software’s specification should be able to affect the specification of the class.
• Software entities should be open for extension, but closed for modification.
• Entities must depend on abstractions, not on concrete implementations.

Question 33: What is a namespace?

• a group of generic collections—in a logical hierarchy by function—that enable you to access the core functionality you need in your applications
• a group of methods—in a logical hierarchy by class—that enable you to access the core functionality you need in .NET
• a group of assemblies—in a logical hierarchy by function—that enable you to access the core functionality you need in your applications
• a group of classes, structures, interfaces, enumerations, and delegates—organized in a logical hierarchy by function that enable you to access the core functionality you need in your applications

Question 34: Which of the following selects an anonymous type?

• select new {a. Country, a. Region}
• select a
• select a. Country, a. Region
• select {a. Country, a. Region}

Question 35: Which is NOT true about a constant variable?

• At compile time, the value is evaluated.
• Only at declaration can it be initialized.
• At runtime, its value is evaluated.
• It cannot be static.

Question 36: What is the purpose of CLR?

• CLR performs various operations such as security checks, spell checks, assembly loading, and thread management. It provides a secure execution environment for the internet.
• CLR sets the rules developers must use for the components that are interlanguage compatible. CLR is reusable across all the .NET-compliant languages.
• CLR is a compiler that converts Intermediate Language to a native code.
• CLR performs various operations such as memory management, security checks, assembly loading, and thread management. It also provides a secure execution environment for applications.

Question 37: What is CIL?

• Formerly known as MSIL, CIL is a programming language that NET developers use. It represents the lowest possible level for a language that humans can still read.
• CIL is an object-oriented programming language that is a partially compiled code that .NET developers will then compile to native machine code.
• CIL is used to convert a value type to an object type.
• CIL is a compiled code library that Microsoft developed as an open specification. Developers use it for security, versioning, and deployment purposes.

Question 38: _ pattern works as a bridge between two incompatible interfaces? // wording in question is maybe changed?

• Adapter
• Bridge
• Singleton
• Builder

Question 39: Why would you use ahead-of-time (AOT) compilation?

• You can deliver a faster startup time, especially in big applications where much code executes on startup.
• You have a slow processor.
• You have little memory and disk space
• The JIT compiler does not have to do a lot of disk I/O actions, which are quite expensive.

Question 40: Which statement describes a Dispose method?

• It defines an execution environment for program code and manages the CLR
• It belongs to the IDisposable interface and is used to free resources, such as network connection and files.
• It is partially method-compiled code library for use in deployment, versioning, and security.
• It is used for encapsulation of collections tied to functions of a class and object.

Question 41: What is a thread?

• A single operation that does not return a value and that usually executes asynchronously
• the basic unit to which an operating system allocates processor time
• a series of related tasks or methods that together turn inputs into outputs
• a program that is running on your computer

Question 42: You want to add responsibilities to object dynamically. Which design pattern best fit this objective?

• Decorator
• Bridge
• Singleton
• Facade

Question 43: Which choice creates an 8-tuple containing prime numbers that are less than 20?

• var primes = Tuple.Create(2, 3, 5, 7, 11, 13, 17, 19);
• var primes = Tuple.Create(2, 3, 5, 7, 11, 13, 17, 21);
• var primes = Tuple.Make(2, 3, 5, 7, 11, 13, 17, 20);
• var primes = Tuple.Make(2, 3, 5, 7, 11, 13, 17, 19);

Question 44: How can you recieve form data without a model binder in a controller action?

• public IFormResult ReceivedDataByRequest () {string theName = Request.Forms[“theName”]; return View ();}
• public IActionResult ReceivedDataByRequest () {string theName = Request.Forms[“theName”]; return View ();}
• public IFormResult ReceivedDataByRequest () {string theName = Request.Form[“theName”]; return View ();}
• public IActionResult ReceivedDataByRequest () {string theName = Request.Form[“theName”]; return View ();}

Question 45: Where should you store connection string information?

• in any file within the namespace of the program
• in the view
• in configuration files
• in the database

Question 46: Why use design patterns?

• design patterns make the code more efficient with memory usage
• design patterns minimize the number of code lines when creating complex applications
• design patterns tend to be more secure and prevent code from being hacked
• design patterns help you solve issues related to software development using a proven solution, and make communication between developers more efficient

Question 47: What is a task?

• the basic unit to which an operating system allocates processor time
• a program that is running on your compiler
• a single operation that does not return a value and that usually executes asynchronously
• a series of related methods that together turn inputs into outputs

Question 48: Which choice is NOT a component of .NET Framework?

• common language JIT
• .NET framework class library
• common language runtime
• side-by-side execution

Question 49: Which statement about the this keyword is not true?

• This keyword lets a constructor call a different constructor in the same class.
• A constructor can use a base statement and this statement if the base statement comes first.
• A constructor can use one this statement at most.
• If a constructor uses this statement, its code is executed after the invoked constructor is executed.

Question 50: When should you use the .NET Core class library project type?

• when you want to increase the .NET API surface area your library can access, and allow only .NET Core apps to be compatible with your library
• when you want to increase the number of apps that are compatible with your library, and decrease the .NET API surface area your library can access
• when you want to decrease speed but have more features
• when you want to increase compilation speed and have fewer features

Question 51: Why would the .NET Framework use Normal-JIT (Just-in-Time)?

• to compile complete source code into native code in a single compilation cycle during deployment of the application
• to compile only the methods that are called at runtime and remove them from memory after execution
• to compile only the methods that are called at runtime and them store them in cache for one minute
• to compile only methods called at runtime – which are compiled the first time the methods are called and then stored in a cache to be used for execution when the same methods are called again

Question 52: What is .NET?

• .NET is a general-purpose programming language. The language has expanded significantly over time, and now has object-oriented, generic, and functional features in addition to facilities for low-level memory manipulation.
• .NET is a virtual machine that enables a computer to run programs written in several languages and compile programs to bytecode.
• .NET is an interpreted, high-level, general-purpose programming language. Its language constructs an object-oriented approach aimed at helping programmers write clear, logical code for small and large-scale projects.
• .NET is a free, cross-platform, open-source developer platform for building many different types of applications with multiple languages, editors, and libraries for web, mobile, desktop, gaming, and IoT.

Question 53: The ASP.NET Core Module is a native IIS module that plugs into the IIS pipeline to either _.

• host an ASP.NET Code app inside of the IIS worker process, called the out-of-process hosting model, or forward web requests to a backend ASP.NET Core app running the Kesrel server, called the in-process hosting model
• create IIS code the server needs in a file with the extension required, or run the IIS server in a mode compatible for ASP.NET Core
• package up your C# application and C# packages into .NET modules, or specify which of its packages should be visible to other .NET modules
• host an ASP.NET Code app inside of the IIS workes process, called the in-process hosting model, or forward web requests to a backend ASP.NET Core app running the Kestrel server, called the out-of-process hosting model

Question 54: In the code below, what is the difference between RenderPartial and RenderAction?

@{

Html.RenderAction(“Add”);

Html.RenderPartial(“Add”);

}

• RenderPartial will call an action method of the current controller and render a result inline. RenderAction will render the specified view inline without calling any action method.
• RenderAction will call an action method of the current model and render a result inline. RenderPartial will render the specified view inline without calling any action method.
• RenderAction will call an action method of the current controller and render a result inline. RenderPartial will render the specified view inline without calling any action method.
• RenderPartial will call an action method of the current model and render a result inline. RenderAction will render the specified view inline without calling any action method.

Question 55: What is the Liskov substitution principle?

• Many client-specific interfaces are better than one general-purpose interface.
• Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.
• A class should have only a single responsibility — that is, only changes to one part of the software’s specification should be able to affect the specification of the class.
• Software entities should be open for extension, but closed for modification.

Question 56: What method do you use to explicitly kill a user’s session?

• Session.Timeout()
• Session.Abandon()
• Session.KillAll()
• Session.Remove()

Question 57: Which choice best describes the difference between globalization and localization?

• Localization enables the .NET runtime to provide services to managed code so language compilers can emit metadata and references in your code. Globalization reverses this process.
• Globalization enables the .NET runtime to provide services to managed code so language compilers can emit metadata and references in your code. Localization reverses this process.
• Localization involves designing and developing a world-ready app that supports localized interfaces and regional data for users in multiple cultures. Globalization is the process of translating an application’s resources into versions for each culture that the application will support.
• Globalization involves designing and developing a world-ready app that supports localized interfaces and regional data for users in multiple cultures. Localization is the process of translating an application’s resources into versions for each culture that the application will support.

Question 58: What does CIL stand for?

• C# Interpreted Language
• Common Intermediate Language
• Commonly Interpreted Language
• C# Intermediate Language

Question 59: Which choice best describes the difference between a namespace and an assembly?

• Namespace contains code to form MSIL (Microsoft Intermediate Language). An assembly contains a set of unique names.
• Namespace is the logical naming decided at design time by the developer. Scope for a particular type is defined at run time using an assembly.
• A namespace has logical units that are physically grouped together. An assembly does not have any classification.
• A namespace has logical units that are physically grouped together for assemblies. Assembly classes are available in your program and will be logically grouped.

Question 60: What is a tuple?

• A data structure that has a specific number and sequence of elements
• An object to store multiple variables of the same type in an array data structure
• A group of classes designed specifically for grouping together objects and performing tasks on them
• An array whose elements are jagged

Question 61: What does IL stand for?

• Intermediate Language
• Intelligent Language
• Intelligent Linq
• Interpreted Language

Question 62: You want to create an instance of several families of classes. Which design pattern best fits this objective?

• Decorator
• Singleton
• Abstract Factory
• Bridge

Question 63: Which statement about a read-only variable is not true?

• It can be either static or an instance member.
• At run time, its value is evaluated.
• It can be initialized in either the constructor or the declaration.
• It can be initialized at declaration only.

Question 64: What is the interface segregation principle?

• Many client-specific interfaces are better than one general-purpose interface.
• Software entities should be open for extension, but closed for modification.
• A class should have only a single responsibility – that is, only changes to one part of the software’s specification should be able to affect the specification of the class.
• Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.

Question 65: Which choice is a set of features that extends the query capabilities of the .NET language syntax by adding sets of new standard query operators that allow data manipulation, regardless of the data source?

• XAML
• C#
• XML
• LINQ

Question 66: Why would the .NET Framework use Econo-JIT (Just-inTime)?

• to compile only the methods that are called at run time and then store them in cache for one minute
• to compile only methods called at run time – which are compiled the first time the methods are called and then stored in cache to be used for execution when the same methods are called again
• to compile complete source code into native code in a single compilation cycle during deployment of the application
• to compile only the methods that are called at run time and remove them from memory after execution

Question 67: What is the difference between a heap and a stack?

• The stack contains stored value types; the heap contains stored reference types.
• The heap is stored value types; the stack is stored reference types.
• The heap is stored object types; the stack is stored class types.
• The stack is stored object types; the heap is stored class types.

Question 68: How do you make sure that the garbage collector is done running when you call GC. Collect ()?

• There is no way to find this out.
• You cannot. GC. Collect () is a blocking method, and will return only once the garbage collector is done running.
• by calling GC. WaitForFullGCComplete ()
• by calling GC. WaitForPendingFinalizers ()

Question 69: What does JIT do in .Net?

• JIT is used for deployment, versioning, and security.
• JIT translates the IL code to an assembly code and uses the CPU architecture of the target machine to execute a .NET application.
• JIT compiles to C# code using .NET environment properties.
• JIT is used for deployment, versioning, and security, and forces the computer’s processor to execute the native machine code.

Introduction to LinkedIn .NET Framework

LinkedIn, like many large-scale web applications, has historically used the .NET Framework for its backend services and various components. The .NET Framework is a robust and mature platform developed by Microsoft, widely adopted for building web applications, services, and other types of software.

Here are some aspects where LinkedIn might have used the .NET Framework:

1. Backend Services: LinkedIn’s backend services, responsible for handling user authentication, data storage, messaging, and other core functionalities, could have been developed using ASP.NET, which is part of the .NET Framework.
2. APIs: LinkedIn likely exposes APIs for integration with third-party services and applications. These APIs could be built using ASP.NET Web API, a framework within the .NET ecosystem that facilitates building RESTful services.
3. Job Scheduler: LinkedIn might use the Task Scheduler within the .NET Framework to manage background jobs, such as processing updates, notifications, or analytics tasks.
4. Caching: Caching mechanisms are crucial for performance in large-scale applications like LinkedIn. The .NET Framework includes caching solutions such as ASP.NET Output Cache and in-memory caching mechanisms that LinkedIn could utilize.
5. Windows Services: For tasks that run independently of user interaction, LinkedIn could employ Windows Services developed using .NET, which can run in the background on servers.
6. SQL Server Integration: Many .NET applications, including those using the .NET Framework, integrate closely with SQL Server for data storage and retrieval. LinkedIn might use Entity Framework, a popular ORM (Object-Relational Mapper) within the .NET ecosystem, to interact with SQL Server databases.
7. Performance Monitoring: LinkedIn would likely use tools and libraries from the .NET ecosystem for monitoring application performance, identifying bottlenecks, and optimizing code.
8. Security: .NET Framework provides robust security features such as authentication, authorization, and encryption, which LinkedIn would leverage to protect user data and ensure secure communication.

However, it’s important to note that LinkedIn’s technology stack evolves over time. As of the current date, they might be transitioning towards .NET Core (now .NET 6 and later .NET 7), which is a cross-platform successor to the .NET Framework, offering enhanced performance, scalability, and support for modern development practices.