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ASP.NET Web API MCQ questions

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ASP.NET Web API tutorial Interview questions

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ASP.NET Web API practice testMultiple choice Question 1 of 10

What does “stateless” mean for a REST API?

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All questions with answers

Which base class do Web API 2 controllers inherit from?
- AController
- BApiController
- CControllerBase
- DHttpController
Show answer
Answer: B. ApiController
System.Web.Http.ApiController.
Where is Web API routing configured?
- ARouteConfig.cs
- BWebApiConfig.Register
- CProgram.cs
- DStartup.Configure only
Show answer
Answer: B. WebApiConfig.Register
App_Start/WebApiConfig.cs is called from Global.asax.
What is the default Web API route template?
- A{controller}/{action}/{id}
- Bapi/{controller}/{id}
- Capi/{action}
- D{controller}/{id}
Show answer
Answer: B. api/{controller}/{id}
Actions are chosen by HTTP method, so the template has no {action}.
Which return type lets an action return different HTTP results?
- Astring
- BIHttpActionResult
- Cvoid
- Dobject
Show answer
Answer: B. IHttpActionResult
Helpers like Ok(), NotFound() and BadRequest() return IHttpActionResult.
Which helper returns 201 with a Location header?
- AOk()
- BCreatedAtRoute("DefaultApi", new { id }, dto)
- CRedirect()
- DContent()
Show answer
Answer: B. CreatedAtRoute("DefaultApi", new { id }, dto)
CreatedAtRoute builds the location from a named route.
By default, where does Web API bind an int parameter from?
- AThe body
- BThe URI
- CHeaders
- DCookies
Show answer
Answer: B. The URI
Simple types come from the route or query string.
Which attribute forces a simple type to be read from the body?
- A[FromUri]
- B[FromBody]
- C[FromQuery]
- D[FromForm]
Show answer
Answer: B. [FromBody]
Only one parameter per action can use [FromBody].
What chooses JSON or XML for the response?
- AModel binding
- BContent negotiation using the Accept header
- CRouting
- DIIS
Show answer
Answer: B. Content negotiation using the Accept header
Formatters are chosen from the Accept header and media types.
Which class handles requests before they reach controllers?
- AActionFilterAttribute
- BDelegatingHandler
- CModelBinder
- DMediaTypeFormatter
Show answer
Answer: B. DelegatingHandler
Message handlers sit at the start of the pipeline.
Which interface implements a global exception logger?
- AIExceptionLogger
- BIErrorFilter
- CILogger<T>
- DIHttpModule
Show answer
Answer: A. IExceptionLogger
IExceptionLogger logs; IExceptionHandler shapes the response.
Which package adds Swagger to Web API 2?
- ASwashbuckle
- BNSwag.AspNetCore
- CScalar
- DMicrosoft.AspNetCore.OpenApi
Show answer
Answer: A. Swashbuckle
Swashbuckle (the classic package) generates Swagger for Web API 2.
Which attribute protects an action with bearer tokens?
- A[Authorize]
- B[RequireToken]
- C[Secure]
- D[ApiKey]
Show answer
Answer: A. [Authorize]
With OWIN bearer middleware configured, [Authorize] checks the token.
Which call enables CORS attributes in Web API 2?
- Aapp.UseCors()
- Bconfig.EnableCors()
- Cservices.AddCors()
- Droutes.EnableCors()
Show answer
Answer: B. config.EnableCors()
Then apply [EnableCors] to controllers or globally.
What is wrong with this action?
C# Illustrative
```
1public IHttpActionResult Get(int id)
2{
3    var product = _service.GetAsync(id).Result;
4    return Ok(product);
5}
```
- ANothing
- BIt blocks a thread with .Result instead of awaiting
- CAsync actions are not supported
- DIt must return void
Show answer
Answer: B. It blocks a thread with .Result instead of awaiting
Make the action async and await the call; .Result can deadlock in ASP.NET.
Which ADO.NET object executes a stored procedure?
- ASqlConnection
- BSqlCommand with CommandType.StoredProcedure
- CDataSet
- DSqlBulkCopy
Show answer
Answer: B. SqlCommand with CommandType.StoredProcedure
Add parameters and call ExecuteReaderAsync or ExecuteNonQueryAsync.
Which EF6 method saves changes asynchronously?
- ASaveChangesAsync()
- BCommitAsync()
- CFlushAsync()
- DUpdateAsync()
Show answer
Answer: A. SaveChangesAsync()
SaveChangesAsync writes tracked changes in a transaction.
Which setting raises the IIS request size limit?
- AmaxAllowedContentLength in requestFiltering
- BmaxJsonLength
- CexecutionTimeout
- DmaxUrlLength
Show answer
Answer: A. maxAllowedContentLength in requestFiltering
Also raise httpRuntime maxRequestLength (in KB).
Which status code is correct for an unsupported Content-Type?
- A400
- B406
- C415
- D422
Show answer
Answer: C. 415
415 Unsupported Media Type; 406 is for an unsatisfiable Accept header.
What is the main reason to migrate to ASP.NET Core?
- AWeb API 2 cannot return JSON
- BCross-platform hosting, performance and active development
- CCore does not need HTTPS
- DWeb API 2 has no routing
Show answer
Answer: B. Cross-platform hosting, performance and active development
.NET Framework only receives maintenance; ASP.NET Core is where new features land.
Which pagination response is most helpful?
- AOnly the items
- BItems plus page, pageSize and totalCount
- COnly totalCount
- DA redirect to the next page
Show answer
Answer: B. Items plus page, pageSize and totalCount
Metadata lets clients build pagers.
Which base class does a Web API 2 controller inherit?
- AController
- BApiController
- CControllerBase
- DHttpHandler
Show answer
Answer: B. ApiController
Web API 2 controllers inherit System.Web.Http.ApiController.
From the lesson: Introduction to Web APIs
Where is WebApiConfig.Register called from?
- AProgram.cs
- BGlobal.asax Application_Start
- Cweb.config
- DEach controller
Show answer
Answer: B. Global.asax Application_Start
GlobalConfiguration.Configure(WebApiConfig.Register) runs in Application_Start.
From the lesson: Introduction to Web APIs
ASP.NET Web API 2 runs on Linux without changes.
- ATrue
- BFalse
Show answer
Answer: B. False
It requires .NET Framework, which is Windows-only.
From the lesson: Introduction to Web APIs
Which URL follows REST conventions to delete product 7?
- APOST /api/deleteProduct?id=7
- BGET /api/products/7/delete
- CDELETE /api/products/7
- DDELETE /api/product/remove/7
Show answer
Answer: C. DELETE /api/products/7
The resource is in the URL; the action is the HTTP method.
From the lesson: REST Principles
What does “stateless” mean for a REST API?
- AIt has no database
- BEach request contains all the information needed to process it
- CIt never returns errors
- DIt does not use HTTP headers
Show answer
Answer: B. Each request contains all the information needed to process it
The server keeps no client session between requests.
From the lesson: REST Principles