{"department":"Back-End Development","description":null,"descriptionStatus":null,"descriptionUpdatedAt":null,"id":"14cdf860-1cfd-488e-b4de-46b9b02a0f29","label":"ASP.NET","shortDescription":null,"slug":"asp-net","updatedAt":"2023-09-11T07:00:34.832Z","quizzes":[{"difficulty":"beginner","id":"4nImF2InSo","questionCount":15,"questions":[{"index":0,"options":["Model-View-Context","Model-View-Controller","Method-View-Controller","Model-Variable-Controller"],"question":"What does MVC stand for in ASP.NET MVC?","difficulty":"beginner","explanation":"MVC stands for Model-View-Controller, which is a design pattern used to separate application logic into three interconnected parts.","correctIndex":1},{"index":1,"options":[".cshtml",".asp",".cs",".html"],"question":"What is the default file extension for Razor view files in ASP.NET Core?","difficulty":"beginner","explanation":"Razor view files use the .cshtml extension, which allows developers to mix HTML with C# code using Razor syntax.","correctIndex":0},{"index":2,"options":["Models","App_Data","wwwroot","Views"],"question":"In ASP.NET Core, which folder is intended to serve static files like CSS, JavaScript, and images?","difficulty":"beginner","explanation":"The wwwroot folder is the web root of the application where static files are stored and served directly to clients.","correctIndex":2},{"index":3,"options":["Controller","ApiController","PageModel","ControllerBase"],"question":"Which base class do ASP.NET Core MVC controllers typically inherit from?","difficulty":"beginner","explanation":"MVC controllers typically inherit from the Controller class, which provides methods and properties for handling requests and returning views.","correctIndex":0},{"index":4,"options":["Startup.cs","web.config","Program.cs","appsettings.json"],"question":"In ASP.NET Core, where are application configuration settings, such as database connection strings, typically stored?","difficulty":"beginner","explanation":"Application settings and configuration in ASP.NET Core are typically stored in the appsettings.json file.","correctIndex":3},{"index":5,"options":["To mark the action as secure","To restrict the action to only handle HTTP GET requests","To generate a hyperlink","To retrieve data from the session"],"question":"What is the purpose of the [HttpGet] attribute on a controller action?","difficulty":"beginner","explanation":"The [HttpGet] attribute specifies that an action method should only respond to HTTP GET requests.","correctIndex":1},{"index":6,"options":["@variable","<%: variable %>","#variable","{{ variable }}"],"question":"Which of the following is the correct Razor syntax to display a variable's value in a view?","difficulty":"beginner","explanation":"In Razor syntax, the @ symbol is used to transition from HTML to C# code, so @variable will output the value of the variable.","correctIndex":0},{"index":7,"options":["/{controller}/{action}/{id?}","{controller}/{action}/{id}","{action}/{controller}/{id}","{controller=Home}/{action=Index}/{id?}"],"question":"What is the default routing pattern configured in a standard ASP.NET Core MVC application?","difficulty":"beginner","explanation":"The default route template in ASP.NET Core MVC is {controller=Home}/{action=Index}/{id?}, which sets default values for the controller and action.","correctIndex":3},{"index":8,"options":["Run()","Start()","Init()","Build()"],"question":"Which method in Program.cs is used to start the ASP.NET Core web application?","difficulty":"beginner","explanation":"The Run() method is called on the WebApplication instance to start the application and block the calling thread until the host shuts down.","correctIndex":0},{"index":9,"options":["ViewBag","ViewModel","All of the above","TempData"],"question":"Which of the following can be used to pass data from a controller to a view in ASP.NET MVC?","difficulty":"beginner","explanation":"ViewBag, ViewModel, and TempData are all valid mechanisms to pass data from a controller to a view in ASP.NET MVC.","correctIndex":2},{"index":10,"options":["app.UseMvc()","app.UseAuthentication()","app.UseStaticFiles()","app.UseRouting()"],"question":"Which ASP.NET Core middleware component must be added to the pipeline to enable serving static files from the wwwroot folder?","difficulty":"beginner","explanation":"The app.UseStaticFiles() middleware enables serving static files from the web root (wwwroot) folder.","correctIndex":2},{"index":11,"options":["Providing dependencies to classes instead of having classes create them","Managing database connections","Securing API endpoints","Rendering HTML views"],"question":"What does Dependency Injection (DI) in ASP.NET Core primarily help with?","difficulty":"beginner","explanation":"Dependency Injection is a design pattern that provides class dependencies from external sources rather than having the classes instantiate them directly.","correctIndex":0},{"index":12,"options":["200","404","500","301"],"question":"Which HTTP status code typically indicates that a requested resource was not found?","difficulty":"beginner","explanation":"HTTP status code 404 indicates that the server cannot find the requested resource.","correctIndex":1},{"index":13,"options":["To handle user input and interactions","To render the user interface","To route incoming requests","To manage the application's data and business logic"],"question":"What is the role of the Model in the ASP.NET MVC pattern?","difficulty":"beginner","explanation":"The Model represents the application's data structure and business logic, independent of the user interface.","correctIndex":3},{"index":14,"options":["It binds data from the HTTP request to the property","It binds the property to a database column","It encrypts the property value","It caches the property value in memory"],"question":"In ASP.NET Core Razor Pages, what does the [BindProperty] attribute do when applied to a property in a PageModel?","difficulty":"beginner","explanation":"The [BindProperty] attribute allows model binding to assign values from an HTTP request to the decorated property on a PageModel.","correctIndex":0}]},{"difficulty":"intermediate","id":"OIk70m17zB","questionCount":15,"questions":[{"index":0,"options":["Singleton with IDisposable","Transient","Singleton","Scoped"],"question":"In ASP.NET Core, which service lifetime should typically be used for Entity Framework DbContext when following standard patterns?","difficulty":"intermediate","explanation":"DbContext should be scoped because it is not thread-safe and should be shared within a single request but not across different requests.","correctIndex":3},{"index":1,"options":["app.UseAuthentication()","app.UseRouting()","app.UseExceptionHandler()","app.UseAuthorization()"],"question":"In ASP.NET Core middleware configuration, which middleware should be registered early in the pipeline to ensure exceptions from subsequent middleware are caught?","difficulty":"intermediate","explanation":"UseExceptionHandler should be registered early so it can catch exceptions thrown by middleware registered after it in the pipeline.","correctIndex":2},{"index":2,"options":["IOptions","IOptionsMonitor","IOptionsFactory","IOptionsSnapshot"],"question":"When using the Options pattern in ASP.NET Core, which interface provides change notification when configuration values are updated at runtime?","difficulty":"intermediate","explanation":"IOptionsMonitor supports change notifications and reloads configuration values when the underlying source changes, making it suitable for runtime configuration updates.","correctIndex":1},{"index":3,"options":["[Authorize(Policy = \"Policy1 && Policy2\")]","[Authorize(Policy = \"Policy1\")][Authorize(Policy = \"Policy2\")]","[Authorize(Policy = \"Policy1,Policy2\")]","[Authorize(Policies = new[] {\"Policy1\", \"Policy2\"})]"],"question":"In ASP.NET Core, how do you apply multiple authorization policies that must ALL be satisfied for a controller action?","difficulty":"intermediate","explanation":"Stacking multiple [Authorize] attributes with different policies creates an AND requirement, meaning all specified policies must be satisfied for access.","correctIndex":1},{"index":4,"options":["Use exception filters when you need to handle errors only from controller actions, middleware for pipeline-wide errors","Exception filters are better for all error handling scenarios","Exception filters handle exceptions from middleware","Middleware cannot handle exceptions from controllers"],"question":"In ASP.NET Core MVC, when should you use an exception filter versus middleware for error handling?","difficulty":"intermediate","explanation":"Exception filters only catch exceptions from controller actions and action results, while middleware can handle exceptions from anywhere in the request pipeline.","correctIndex":0},{"index":5,"options":["asp-route","asp-action","asp-page","asp-controller"],"question":"Which Tag Helper attribute is used in ASP.NET Core Razor Pages to specify which page a form should submit to?","difficulty":"intermediate","explanation":"In Razor Pages, asp-page is used to specify the target page for form submission, while asp-action and asp-controller are MVC-specific attributes.","correctIndex":2},{"index":6,"options":["There is no difference; they are interchangeable","View Components can only render HTML, Partial Views can render any content","View Components have their own logic and support dependency injection, Partial Views rely on the parent view's model","Partial Views are cached by default, View Components are not"],"question":"What is the primary difference between a View Component and a Partial View in ASP.NET Core?","difficulty":"intermediate","explanation":"View Components encapsulate their own logic and support dependency injection through their InvokeAsync method, while Partial Views share the parent view's model and context.","correctIndex":2},{"index":7,"options":["Add it as a request header after reading it from a meta tag or hidden input","Anti-forgery tokens are not needed for AJAX requests","Add it as a query string parameter","Include it in the request body as a form field"],"question":"When making AJAX requests from JavaScript in ASP.NET Core, what is the recommended way to include the anti-forgery token?","difficulty":"intermediate","explanation":"ASP.NET Core supports reading anti-forgery tokens from request headers, which is the recommended approach for AJAX calls since it avoids modifying the request body format.","correctIndex":0},{"index":8,"options":["services.AddOptions(Configuration.GetSection(\"MyOptions\"))","services.Bind(Configuration.GetSection(\"MyOptions\"))","services.Configure(Configuration.GetSection(\"MyOptions\"))","services.Register(Configuration.GetSection(\"MyOptions\"))"],"question":"Which method is used to bind a configuration section to a strongly-typed options class in ASP.NET Core's dependency injection?","difficulty":"intermediate","explanation":"services.Configure binds a configuration section to the options type and registers it with the DI container so it can be injected via IOptions.","correctIndex":2},{"index":9,"options":["The id parameter will be converted to int if possible, otherwise set to null","The id parameter must be a positive integer","The id parameter must be an integer and is required","The id parameter must be any integer value (positive or negative)"],"question":"In ASP.NET Core attribute routing, what does the route template constraint \"{id:int}\" enforce?","difficulty":"intermediate","explanation":"The :int constraint enforces that the id parameter value must be parseable as an integer (positive or negative), but does not make the parameter required unless a ? suffix is added.","correctIndex":3},{"index":10,"options":["BackgroundService is an abstract class that simplifies implementing IHostedService for long-running tasks via ExecuteAsync","BackgroundService cannot be stopped gracefully","IHostedService runs in a separate process","IHostedService cannot be registered as scoped"],"question":"What is the key difference between IHostedService and BackgroundService in ASP.NET Core?","difficulty":"intermediate","explanation":"BackgroundService is a base class implementing IHostedService that provides a simpler pattern for long-running background tasks by overriding ExecuteAsync, which handles the cancellation token lifecycle.","correctIndex":0},{"index":11,"options":["When you need to modify the model before binding","When you need access to MVC context like ModelState","When you need to affect all requests regardless of whether they reach a controller","When you need to run logic after model validation"],"question":"When should you use middleware instead of an action filter in ASP.NET Core?","difficulty":"intermediate","explanation":"Middleware runs for all requests in the pipeline regardless of whether they reach a controller, while action filters only execute for requests that reach a controller action.","correctIndex":2},{"index":12,"options":["services.AddHealthChecks().AddSqlServer(connectionString)","services.ConfigureHealthCheck(\"sql\", connectionString)","services.AddSqlServerHealthCheck(connectionString)","services.AddDbContextHealthCheck(connectionString)"],"question":"In ASP.NET Core, how do you register a health check for a SQL Server database dependency?","difficulty":"intermediate","explanation":"AddHealthChecks() returns an IHealthChecksBuilder that provides extension methods like AddSqlServer for registering health checks for common dependencies.","correctIndex":0},{"index":13,"options":["[FromRoute]","[FromForm]","[FromQuery]","[FromBody]"],"question":"In an ASP.NET Core API controller, which attribute specifies that a parameter should be bound from the HTTP request body?","difficulty":"intermediate","explanation":"[FromBody] specifies that a parameter should be bound from the HTTP request body, typically for JSON or XML content in API controllers.","correctIndex":3},{"index":14,"options":["Caches the response on the server for 60 seconds","Sets the Cache-Control HTTP header to instruct clients and proxies to cache the response for 60 seconds","Invalidates the server cache every 60 seconds","Caches the response in memory for 60 seconds"],"question":"What does the [ResponseCache(Duration = 60)] attribute do in ASP.NET Core without additional Response Caching Middleware?","difficulty":"intermediate","explanation":"Without Response Caching Middleware, [ResponseCache] only sets the Cache-Control HTTP header with a max-age of 60 seconds, instructing clients and proxies to cache the response.","correctIndex":1}]},{"difficulty":"advanced","id":"RPzPmWL53h","questionCount":15,"questions":[{"index":0,"options":["An InvalidOperationException is thrown at application startup","The scoped service is resolved once and held for the lifetime of the singleton, violating scope boundaries","A new scope is automatically created for each call to the singleton","The DI container returns a transient instance instead of a scoped one"],"question":"In an ASP.NET Core application running in the Production environment with default DI configuration, what happens when a Singleton service directly depends on a Scoped service via constructor injection?","difficulty":"advanced","explanation":"In Production, scope validation (ValidateScopes) is disabled by default, so the scoped service is 'captured' and lives as long as the singleton. In Development, ValidateScopes is enabled and would throw an exception.","correctIndex":1},{"index":1,"options":["Using [ApiController] attribute on the controller","Using async/await within the action method","Response compression middleware or output caching that requires full buffering","Returning the IAsyncEnumerable from a synchronous action method"],"question":"In an ASP.NET Core controller action, when returning IAsyncEnumerable, what can prevent the response from being streamed to the client?","difficulty":"advanced","explanation":"While IAsyncEnumerable enables streaming by default, response compression middleware must buffer the entire response to compute the compressed output, and output caching similarly requires full buffering, negating the streaming benefit.","correctIndex":2},{"index":2,"options":["It creates a dependency on AsyncLocal storage that may return null or stale context when accessed from background threads or outside the request pipeline","It causes thread pool starvation because each request allocates a new AsyncLocal storage slot","It automatically promotes the singleton to scoped lifetime in the DI container","It will throw an InvalidOperationException at runtime because IHttpContextAccessor cannot be injected into singletons"],"question":"Which statement best describes the risk of injecting IHttpContextAccessor into a Singleton service?","difficulty":"advanced","explanation":"IHttpContextAccessor relies on AsyncLocal to flow HttpContext with the execution context. When a singleton is accessed from background threads (e.g., IHostedService), the context will be null, and in edge cases with custom task scheduling, stale context may be observed.","correctIndex":0},{"index":3,"options":["Register the scoped service as transient in the DI container","Inject the scoped service directly into the BackgroundService constructor","Inject IServiceScopeFactory, create a scope within ExecuteAsync, and resolve services from that scope","Inject IServiceProvider and resolve the scoped service directly on each iteration"],"question":"When implementing a BackgroundService that needs to resolve and use scoped services (e.g., a DbContext), what is the correct approach?","difficulty":"advanced","explanation":"BackgroundService is registered as a singleton. Using IServiceScopeFactory to create a scope within ExecuteAsync ensures proper scope creation and disposal, preventing captive dependency issues and ensuring DbContext and similar services work correctly.","correctIndex":2},{"index":4,"options":["Response caching respects HTTP Cache-Control headers and is limited to in-memory storage; Output caching requires explicit programmatic opt-in and supports distributed cache backends","Response caching requires explicit programmatic opt-in; Output caching respects HTTP Cache-Control headers automatically","Response caching supports distributed cache backends; Output caching is limited to in-memory storage","Response caching is endpoint-aware; Output caching operates only on raw URL patterns without endpoint awareness"],"question":"In ASP.NET Core 7+, what is a key architectural difference between Response Caching middleware and Output Caching middleware?","difficulty":"advanced","explanation":"Response Caching respects HTTP caching semantics (Cache-Control, Vary headers) and is limited to in-memory storage. Output Caching requires explicit opt-in via policy, supports IDistributedCache backends, and provides deterministic programmatic control.","correctIndex":0},{"index":5,"options":["When the logic needs to run before the routing middleware","When the logic needs to modify response headers before the response starts","When the logic needs to access MVC context (e.g., action descriptor, model state) or should only apply to specific actions","When the logic needs to run for every request regardless of whether a matching endpoint exists"],"question":"When should you implement logic as a Resource Filter (IAsyncResourceFilter) rather than as Middleware?","difficulty":"advanced","explanation":"Resource filters run within the MVC/action pipeline and have access to action descriptors, model state, and other MVC context. They can be scoped to specific actions or controllers via attributes, unlike middleware which runs before endpoint resolution.","correctIndex":2},{"index":6,"options":["To cache the endpoint's serialized response for output caching","To configure the DI container for each specific endpoint","To provide cross-cutting information (authorization, CORS, rate limiting) that middleware and filters can inspect without invoking the endpoint","To store per-request runtime data that persists across middleware invocations"],"question":"In ASP.NET Core endpoint routing, what is the primary purpose of endpoint metadata (accessed via HttpContext.GetEndpoint().Metadata)?","difficulty":"advanced","explanation":"Endpoint metadata allows cross-cutting concerns to be associated with endpoints declaratively. Middleware and filters can inspect this metadata early in the pipeline to make authorization, CORS, or rate limiting decisions without executing the endpoint.","correctIndex":2},{"index":7,"options":["Use [FromBody] and send a JSON payload containing all the values","Create separate model binders for each source and chain them using IModelBinderProvider","Apply multiple [From*] attributes to the parameter and let the default binder aggregate them","Implement IModelBinder and read directly from BindingContext.HttpContext.Request and BindingContext.ValueProvider for the different sources"],"question":"When implementing a custom IModelBinder that needs to bind a model from multiple sources (query string, route data, and headers), what is the correct approach?","difficulty":"advanced","explanation":"A custom IModelBinder has full access to the HttpContext and ValueProvider, enabling it to read from any combination of sources. Multiple [From*] attributes cannot be combined on a single parameter, so a custom binder is the correct approach for multi-source binding.","correctIndex":3},{"index":8,"options":["The parameter is deserialized from the request body, ignoring the DI registration","The parameter is resolved from the DI container, not deserialized from the request body","The framework throws an AmbiguousBindingException at startup","The framework attempts both and uses whichever succeeds first"],"question":"In an ASP.NET Core minimal API, what happens when a complex type parameter is registered in the DI container and could also be deserialized from the request body?","difficulty":"advanced","explanation":"In minimal APIs, when a complex type is registered in DI, the framework infers [FromServices] binding, resolving the parameter from the container rather than deserializing from the request body. To bind from the body instead, you must explicitly apply [FromBody].","correctIndex":1},{"index":9,"options":["Configure the anti-forgery system to validate the token from a custom header (e.g., RequestVerificationToken) and include it via JavaScript from a cookie or embedded value","Disable anti-forgery validation for API endpoints and rely solely on CORS policy for protection","Include the anti-forgery token as a hidden field in every AJAX request body","Use cookie-based authentication, which makes anti-forgery tokens unnecessary"],"question":"In an ASP.NET Core application using anti-forgery tokens with AJAX requests, what is the recommended approach for token validation?","difficulty":"advanced","explanation":"The recommended approach for AJAX is to configure anti-forgery to read the token from a custom HTTP header (set via JavaScript from a cookie or embedded in the page), enabling JSON payloads without embedding the token in the body.","correctIndex":0},{"index":10,"options":["The application uses IISHttpServer instead of Kestrel, running directly in the IIS worker process","IIS handles static files while Kestrel handles dynamic requests within the same process","Kestrel receives requests from the ASP.NET Core Module and processes them within the IIS worker process","Requests are proxied from IIS to Kestrel running on a separate internal port"],"question":"When using ASP.NET Core with IIS in-process hosting, which statement about request handling is correct?","difficulty":"advanced","explanation":"In in-process hosting, the application runs in the IIS worker process (w3wp.exe) using IISHttpServer instead of Kestrel. The ASP.NET Core Module forwards requests directly to IISHttpServer without reverse-proxying to Kestrel.","correctIndex":0},{"index":11,"options":["IOptionsMonitor is registered as scoped; IOptionsSnapshot is registered as singleton","IOptionsMonitor caches values indefinitely without refresh; IOptionsSnapshot refreshes on every property access","IOptionsSnapshot supports named options; IOptionsMonitor does not","IOptionsMonitor supports change notifications via OnChange and is singleton-scoped; IOptionsSnapshot provides a consistent snapshot per request scope"],"question":"What is the key difference between IOptionsMonitor and IOptionsSnapshot in an ASP.NET Core application?","difficulty":"advanced","explanation":"IOptionsMonitor is registered as singleton and supports change notifications via IChangeToken and OnChange callbacks. IOptionsSnapshot is registered as scoped and provides a consistent snapshot of options for each request, refreshing at scope boundaries.","correctIndex":3},{"index":12,"options":["It configures the number of consecutive failures before the check reports Unhealthy","It sets the timeout threshold in milliseconds after which the health check is considered failed","It specifies the HTTP status code returned by the health check endpoint when the check fails","It determines whether the health check reports Degraded or Unhealthy when the check fails, allowing nuanced health reporting"],"question":"When implementing IHealthCheck in ASP.NET Core, what is the purpose of the HealthCheckRegistration.FailureStatus property?","difficulty":"advanced","explanation":"The FailureStatus property allows a health check to distinguish between Degraded and Unhealthy states. When the check fails, it reports the specified status rather than defaulting to Unhealthy, enabling more nuanced health reporting in distributed systems.","correctIndex":3},{"index":13,"options":["The callback executes on a background thread, requiring thread-safe access to shared state in the singleton","The callback cannot access the new configuration values, only the old ones","The callback is invoked synchronously, blocking the request thread","The callback is only invoked once and then automatically unsubscribed"],"question":"In an ASP.NET Core application, a Singleton service registers an OnChange callback via IOptionsMonitor. What is a critical concern with this pattern?","difficulty":"advanced","explanation":"IOptionsMonitor's OnChange callback executes on a background thread when configuration changes are detected. Since the singleton may be processing requests concurrently on different threads, any state modified in the callback must be accessed in a thread-safe manner.","correctIndex":0},{"index":14,"options":["They are queued and processed when a permit becomes available, within the queue processing order","They are queued indefinitely until the application restarts","They are forwarded to the next middleware with a rate-limit warning header added","They receive a 429 Too Many Requests response immediately"],"question":"In ASP.NET Core 7+, when configuring a FixedWindowRateLimiter with both PermitLimit and QueueLimit set to non-zero values, what happens to requests that exceed the permit limit but fall within the queue limit?","difficulty":"advanced","explanation":"When QueueLimit is configured, requests that exceed the permit limit but fall within the queue limit are queued and processed in order when permits become available. This allows for burst handling while still enforcing overall rate limits.","correctIndex":0}]}]}

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