ASP.NET Web API Interview Questions
1. What is ASP.NET Web API?
Ans: ASP.NET Web API is a framework for building HTTP services that can reach a broad range of clients including browsers, mobile devices, and IoT devices. It supports both RESTful and RPC-style services.
2. What is the difference between ASP.NET Web API and ASP.NET MVC?
Ans: ASP.NET Web API is designed for building HTTP services, while ASP.NET MVC is a framework for building web applications using the Model-View-Controller (MVC) design pattern.
3. What is a Controller in ASP.NET Web API?
Ans: A Controller in ASP.NET Web API handles HTTP requests and returns HTTP responses. It contains the logic for processing requests and generating responses.
4. What is the purpose of the Route attribute in ASP.NET Web API?
Ans: The Route attribute is used to define the URL pattern and HTTP methods that a controller action should respond to. It maps incoming requests to specific actions.
5. What is the difference between IHttpActionResult and ActionResult in ASP.NET Web API?
Ans: IHttpActionResult is an interface that represents the result of an HTTP action method. ActionResult is a class that implements this interface and is used to return HTTP responses.
6. What is the purpose of the ApiController attribute in ASP.NET Web API?
Ans: The ApiController attribute is used to indicate that a controller is an API controller. It can be used to configure global settings for API controllers, such as route prefixes and authorization filters.
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7. What is the purpose of the HttpGet and HttpPost attributes in ASP.NET Web API?
Ans: The HttpGet and HttpPost attributes are used to specify that a controller action should respond to HTTP GET and POST requests, respectively.
8. What is the purpose of the FromBody attribute in ASP.NET Web API?
Ans: The FromBody attribute is used to indicate that a parameter should be bound from the body of the HTTP request.
9. What is the purpose of the FromQuery attribute in ASP.NET Web API?
Ans: The FromQuery attribute is used to indicate that a parameter should be bound from the query string of the HTTP request.
10. What is the purpose of the FromRoute attribute in ASP.NET Web API?
Ans: The FromRoute attribute is used to indicate that a parameter should be bound from the route data of the HTTP request.
11. What is the purpose of the FromHeader attribute in ASP.NET Web API?
Ans: The FromHeader attribute is used to indicate that a parameter should be bound from the header of the HTTP request.
12. What is the purpose of the FromForm attribute in ASP.NET Web API?
Ans: The FromForm attribute is used to indicate that a parameter should be bound from the form data of the HTTP request.
13. What is the purpose of the FromServices attribute in ASP.NET Web API?
Ans: The FromServices attribute is used to indicate that a parameter should be bound from a registered service in the dependency injection container.
14. What is the purpose of the Produces attribute in ASP.NET Web API?
Ans: The Produces attribute is used to specify that an action method returns a specific HTTP status code. It is used to indicate the expected outcome of an action.
15. What is the purpose of the Consumes attribute in ASP.NET Web API?
Ans: The Consumes attribute is used to specify that an action method consumes a specific HTTP status code. It is used to indicate the expected input of an action.
16. What is the purpose of the HttpResponseMessage attribute in ASP.NET Web API?
Ans: The HttpResponseMessage attribute is used to specify that an action method returns a specific HTTP status code and message. It is used to indicate the expected outcome of an action.
17. What is the purpose of the Authorize attribute in ASP.NET Web API?
Ans: The Authorize attribute is used to specify the authorization policy for a controller or action. It is used to restrict access to specific users or roles.
18. What is the purpose of the EnableCors attribute in ASP.NET Web API?
Ans: The EnableCors attribute is used to enable Cross-Origin Resource Sharing (CORS) for a controller or action. It allows the API to be accessed from different origins.
19. What is the purpose of the SwaggerOperation attribute in ASP.NET Web API?
Ans: The SwaggerOperation attribute is used to specify the operation ID and summary for a controller action. It is used to generate Swagger documentation for the API.
20. What is the purpose of the SwaggerResponse attribute in ASP.NET Web API?
Ans: The SwaggerResponse attribute is used to specify the response type and description for a controller action. It is used to generate Swagger documentation for the API.
21. What is the purpose of the SwaggerTag attribute in ASP.NET Web API?
Ans: The SwaggerTag attribute is used to specify the tag name and description for a controller action. It is used to generate Swagger documentation for the API.
22. What is the purpose of the ApiExplorerSettings attribute in ASP.NET Web API?
Ans: The ApiExplorerSettings attribute is used to configure the settings for the API Explorer in ASP.NET Web API. It specifies the route prefix and other settings for the API Explorer.
23. What is the purpose of the ApiController attribute in ASP.NET Web API?
Ans: The ApiController attribute is used to indicate that a controller is an API controller. It can be used to configure global settings for API controllers, such as route prefixes and authorization filters.
24. What is the purpose of the HttpGet and HttpPost attributes in ASP.NET Web API?
Ans: The HttpGet and HttpPost attributes are used to specify that a controller action should respond to HTTP GET and POST requests, respectively.
25. What is the purpose of the FromBody attribute in ASP.NET Web API?
Ans: The FromBody attribute is used to indicate that a parameter should be bound from the body of the HTTP request.
26. What is the purpose of the FromQuery attribute in ASP.NET Web API?
Ans: The FromQuery attribute is used to indicate that a parameter should be bound from the query string of the HTTP request.
27. What is the purpose of the FromRoute attribute in ASP.NET Web API?
Ans: The FromRoute attribute is used to indicate that a parameter should be bound from the route data of the HTTP request.
28. What is the purpose of the FromHeader attribute in ASP.NET Web API?
Ans: The FromHeader attribute is used to indicate that a parameter should be bound from the header of the HTTP request.
29. What is the purpose of the FromForm attribute in ASP.NET Web API?
Ans: The FromForm attribute is used to indicate that a parameter should be bound from the form data of the HTTP request.
30. What is the purpose of the FromServices attribute in ASP.NET Web API?
Ans: The FromServices attribute is used to indicate that a parameter should be bound from a registered service in the dependency injection container.
31. What is the purpose of the Produces attribute in ASP.NET Web API?
Ans: The Produces attribute is used to specify that an action method returns a specific HTTP status code. It is used to indicate the expected outcome of an action.
32. What is the purpose of the Consumes attribute in ASP.NET Web API?
Ans: The Consumes attribute is used to specify that an action method consumes a specific HTTP status code. It is used to indicate the expected input of an action.
33. What is the purpose of the HttpResponseMessage attribute in ASP.NET Web API?
Ans: The HttpResponseMessage attribute is used to specify that an action method returns a specific HTTP status code and message. It is used to indicate the expected outcome of an action.
34. What is the purpose of the Authorize attribute in ASP.NET Web API?
Ans: The Authorize attribute is used to specify the authorization policy for a controller or action. It is used to restrict access to specific users or roles.
35. What is the purpose of the EnableCors attribute in ASP.NET Web API?
Ans: The EnableCors attribute is used to enable Cross-Origin Resource Sharing (CORS) for a controller or action. It allows the API to be accessed from different origins.
36. What is the purpose of the SwaggerOperation attribute in ASP.NET Web API?
Ans: The SwaggerOperation attribute is used to specify the operation ID and summary for a controller action. It is used to generate Swagger documentation for the API.
37. What is the purpose of the SwaggerResponse attribute in ASP.NET Web API?
Ans: The SwaggerResponse attribute is used to specify the response type and description for a controller action. It is used to generate Swagger documentation for the API.
38. What is the purpose of the SwaggerTag attribute in ASP.NET Web API?
Ans: The SwaggerTag attribute is used to specify the tag name and description for a controller action. It is used to generate Swagger documentation for the API.
39. What is the purpose of the ApiExplorerSettings attribute in ASP.NET Web API?
Ans: The ApiExplorerSettings attribute is used to configure the settings for the API Explorer in ASP.NET Web API. It specifies the route prefix and other settings for the API Explorer.
40. What is the purpose of the ApiController attribute in ASP.NET Web API?
Ans: The ApiController attribute is used to indicate that a controller is an API controller. It can be used to configure global settings for API controllers, such as route prefixes and authorization filters.
41. What is the purpose of the HttpGet and HttpPost attributes in ASP.NET Web API?
Ans: The HttpGet and HttpPost attributes are used to specify that a controller action should respond to HTTP GET and POST requests, respectively.
42. What is the purpose of the FromBody attribute in ASP.NET Web API?
Ans: The FromBody attribute is used to indicate that a parameter should be bound from the body of the HTTP request.
43. What is the purpose of the FromQuery attribute in ASP.NET Web API?
Ans: The FromQuery attribute is used to indicate that a parameter should be bound from the query string of the HTTP request.
44. What is the purpose of the FromRoute attribute in ASP.NET Web API?
Ans: The FromRoute attribute is used to indicate that a parameter should be bound from the route data of the HTTP request.
45. What is the purpose of the FromHeader attribute in ASP.NET Web API?
Ans: The FromHeader attribute is used to indicate that a parameter should be bound from the header of the HTTP request.
46. What is the purpose of the FromForm attribute in ASP.NET Web API?
Ans: The FromForm attribute is used to indicate that a parameter should be bound from the form data of the HTTP request.
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47. What is the purpose of the FromServices attribute in ASP.NET Web API?
Ans: The FromServices attribute is used to indicate that a parameter should be bound from a registered service in the dependency injection container.
48. What is the purpose of the Produces attribute in ASP.NET Web API?
Ans: The Produces attribute is used to specify that an action method returns a specific HTTP status code. It is used to indicate the expected outcome of an action.
49. What is the purpose of the Consumes attribute in ASP.NET Web API?
Ans: The Consumes attribute is used to specify that an action method consumes a specific HTTP status code. It is used to indicate the expected input of an action.
50. What is the purpose of the HttpResponseMessage attribute in ASP.NET Web API?
Ans: The HttpResponseMessage attribute is used to specify that an action method returns a specific HTTP status code and message. It is used to indicate the expected outcome of an action.
51. What is the purpose of the Authorize attribute in ASP.NET Web API?
Ans: The Authorize attribute is used to specify the authorization policy for a controller or action. It is used to restrict access to specific users or roles.
52. What is the purpose of the EnableCors attribute in ASP.NET Web API?
Ans: The EnableCors attribute is used to enable Cross-Origin Resource Sharing (CORS) for a controller or action. It allows the API to be accessed from different origins.
53. What is the purpose of the SwaggerOperation attribute in ASP.NET Web API?
Ans: The SwaggerOperation attribute is used to specify the operation ID and summary for a controller action. It is used to generate Swagger documentation for the API.
54. What is the purpose of the SwaggerResponse attribute in ASP.NET Web API?
Ans: The SwaggerResponse attribute is used to specify the response type and description for a controller action. It is used to generate Swagger documentation for the API.
55. What is the purpose of the SwaggerTag attribute in ASP.NET Web API?
Ans: The SwaggerTag attribute is used to specify the tag name and description for a controller action. It is used to generate Swagger documentation for the API.
56. What is the purpose of the ApiExplorerSettings attribute in ASP.NET Web API?
Ans: The ApiExplorerSettings attribute is used to configure the settings for the API Explorer in ASP.NET Web API. It specifies the route prefix and other settings for the API Explorer.
57. What is the purpose of the ApiController attribute in ASP.NET Web API?
Ans: The ApiController attribute is used to indicate that a controller is an API controller. It can be used to configure global settings for API controllers, such as route prefixes and authorization filters.
58. What is the purpose of the HttpGet and HttpPost attributes in ASP.NET Web API?
Ans: The HttpGet and HttpPost attributes are used to specify that a controller action should respond to HTTP GET and POST requests, respectively.
59. What is the purpose of the FromBody attribute in ASP.NET Web API?
Ans: The FromBody attribute is used to indicate that a parameter should be bound from the body of the HTTP request.
60. What is the purpose of the FromQuery attribute in ASP.NET Web API?
Ans: The FromQuery attribute is used to indicate that a parameter should be bound from the query string of the HTTP request.
61. What is the purpose of the FromRoute attribute in ASP.NET Web API?
Ans: The FromRoute attribute is used to indicate that a parameter should be bound from the route data of the HTTP request.
62. What is the purpose of the FromHeader attribute in ASP.NET Web API?
Ans: The FromHeader attribute is used to indicate that a parameter should be bound from the header of the HTTP request.
63. What is the purpose of the FromForm attribute in ASP.NET Web API?
Ans: The FromForm attribute is used to indicate that a parameter should be bound from the form data of the HTTP request.
64. What is the purpose of the FromServices attribute in ASP.NET Web API?
Ans: The FromServices attribute is used to indicate that a parameter should be bound from a registered service in the dependency injection container.
65. What is the purpose of the Produces attribute in ASP.NET Web API?
Ans: The Produces attribute is used to specify that an action method returns a specific HTTP status code. It is used to indicate the expected outcome of an action.
66. What is the purpose of the Consumes attribute in ASP.NET Web API?
Ans: The Consumes attribute is used to specify that an action method consumes a specific HTTP status code. It is used to indicate the expected input of an action.
67. What is the purpose of the HttpResponseMessage attribute in ASP.NET Web API?
Ans: The HttpResponseMessage attribute is used to specify that an action method returns a specific HTTP status code and message. It is used to indicate the expected outcome of an action.
68. What is the purpose of the Authorize attribute in ASP.NET Web API?
Ans: The Authorize attribute is used to specify the authorization policy for a controller or action. It is used to restrict access to specific users or roles.
69. What is the purpose of the EnableCors attribute in ASP.NET Web API?
Ans: The EnableCors attribute is used to enable Cross-Origin Resource Sharing (CORS) for a controller or action. It allows the API to be accessed from different origins.
70. What is the purpose of the SwaggerOperation attribute in ASP.NET Web API?
Ans: The SwaggerOperation attribute is used to specify the operation ID and summary for a controller action. It is used to generate Swagger documentation for the API.
71. What is the purpose of the SwaggerResponse attribute in ASP.NET Web API?
Ans: The SwaggerResponse attribute is used to specify the response type and description for a controller action. It is used to generate Swagger documentation for the API.
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72. What is the purpose of the SwaggerTag attribute in ASP.NET Web API?
Ans: The SwaggerTag attribute is used to specify the tag name and description for a controller action. It is used to generate Swagger documentation for the API.
73. What is the purpose of the ApiExplorerSettings attribute in ASP.NET Web API?
Ans: The ApiExplorerSettings attribute is used to configure the settings for the API Explorer in ASP.NET Web API. It specifies the route prefix and other settings for the API Explorer.
74. What is the purpose of the ApiController attribute in ASP.NET Web API?
Ans: The ApiController attribute is used to indicate that a controller is an API controller. It can be used to configure global settings for API controllers, such as route prefixes and authorization filters.
75. What is the purpose of the HttpGet and HttpPost attributes in ASP.NET Web API?
Ans: The HttpGet and HttpPost attributes are used to specify that a controller action should respond to HTTP GET and POST requests, respectively.
76. What is the purpose of the FromBody attribute in ASP.NET Web API?
Ans: The FromBody attribute is used to indicate that a parameter should be bound from the body of the HTTP request.
77. What is the purpose of the FromQuery attribute in ASP.NET Web API?
Ans: The FromQuery attribute is used to indicate that a parameter should be bound from the query string of the HTTP request.
78. What is the purpose of the FromRoute attribute in ASP.NET Web API?
Ans: The FromRoute attribute is used to indicate that a parameter should be bound from the route data of the HTTP request.
79. What is the purpose of the FromHeader attribute in ASP.NET Web API?
Ans: The FromHeader attribute is used to indicate that a parameter should be bound from the header of the HTTP request.
80. What is the purpose of the FromForm attribute in ASP.NET Web API?
Ans: The FromForm attribute is used to indicate that a parameter should be bound from the form data of the HTTP request.
81. What is the purpose of the FromServices attribute in ASP.NET Web API?
Ans: The FromServices attribute is used to indicate that a parameter should be bound from a registered service in the dependency injection container.
82. What is the purpose of the Produces attribute in ASP.NET Web API?
Ans: The Produces attribute is used to specify that an action method returns a specific HTTP status code. It is used to indicate the expected outcome of an action.
83. What is the purpose of the Consumes attribute in ASP.NET Web API?
Ans: The Consumes attribute is used to specify that an action method consumes a specific HTTP status code. It is used to indicate the expected input of an action.
84. What is the purpose of the HttpResponseMessage attribute in ASP.NET Web API?
Ans: The HttpResponseMessage attribute is used to specify that an action method returns a specific HTTP status code and message. It is used to indicate the expected outcome of an action.
85. What is the purpose of the Authorize attribute in ASP.NET Web API?
Ans: The Authorize attribute is used to specify the authorization policy for a controller or action. It is used to restrict access to specific users or roles.
86. What is the purpose of the EnableCors attribute in ASP.NET Web API?
Ans: The EnableCors attribute is used to enable Cross-Origin Resource Sharing (CORS) for a controller or action. It allows the API to be accessed from different origins.
87. What is the purpose of the SwaggerOperation attribute in ASP.NET Web API?
Ans: The SwaggerOperation attribute is used to specify the operation ID and summary for a controller action. It is used to generate Swagger documentation for the API.
88. What is the purpose of the SwaggerResponse attribute in ASP.NET Web API?
Ans: The SwaggerResponse attribute is used to specify the response type and description for a controller action. It is used to generate Swagger documentation for the API.
89. What is the purpose of the SwaggerTag attribute in ASP.NET Web API?
Ans: The SwaggerTag attribute is used to specify the tag name and description for a controller action. It is used to generate Swagger documentation for the API.
90. What is the purpose of the ApiExplorerSettings attribute in ASP.NET Web API?
Ans: The ApiExplorerSettings attribute is used to configure the settings for the API Explorer in ASP.NET Web API. It specifies the route prefix and other settings for the API Explorer.
91. What is the purpose of the ApiController attribute in ASP.NET Web API?
Ans: The ApiController attribute is used to indicate that a controller is an API controller. It can be used to configure global settings for API controllers, such as route prefixes and authorization filters.
92. What is the purpose of the HttpGet and HttpPost attributes in ASP.NET Web API?
Ans: The HttpGet and HttpPost attributes are used to specify that a controller action should respond to HTTP GET and POST requests, respectively.
93. What is the purpose of the FromBody attribute in ASP.NET Web API?
Ans: The FromBody attribute is used to indicate that a parameter should be bound from the body of the HTTP request.
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94. What is the purpose of the FromQuery attribute in ASP.NET Web API?
Ans: The FromQuery attribute is used to indicate that a parameter should be bound from the query string of the HTTP request.
95. What is the purpose of the FromRoute attribute in ASP.NET Web API?
Ans: The FromRoute attribute is used to indicate that a parameter should be bound from the route data of the HTTP request.
96. What is the purpose of the FromHeader attribute in ASP.NET Web API?
Ans: The FromHeader attribute is used to indicate that a parameter should be bound from the header of the HTTP request.
97. What is the purpose of the FromForm attribute in ASP.NET Web API?
Ans: The FromForm attribute is used to indicate that a parameter should be bound from the form data of the HTTP request.
98. What is the purpose of the FromServices attribute in ASP.NET Web API?
Ans: The FromServices attribute is used to indicate that a parameter should be bound from a registered service in the dependency injection container.
99. What is the purpose of the Produces attribute in ASP.NET Web API?
Ans: The Produces attribute is used to specify that an action method returns a specific HTTP status code. It is used to indicate the expected outcome of an action.
100. What is the purpose of the Consumes attribute in ASP.NET Web API?
Ans: The Consumes attribute is used to specify that an action method consumes a specific HTTP status code. It is used to indicate the expected input of an action.
101. What is the purpose of the HttpResponseMessage attribute in ASP.NET Web API?
Ans: The HttpResponseMessage attribute is used to specify that an action method returns a specific HTTP status code and message. It is used to indicate the expected outcome of an action.
102. What is the purpose of the Authorize attribute in ASP.NET Web API?
Ans: The Authorize attribute is used to specify the authorization policy for a controller or action. It is used to restrict access to specific users or roles.
103. What is the purpose of the EnableCors attribute in ASP.NET Web API?
Ans: The EnableCors attribute is used to enable Cross-Origin Resource Sharing (CORS) for a controller or action. It allows the API to be accessed from different origins.
104. What is the purpose of the SwaggerOperation attribute in ASP.NET Web API?
Ans: The SwaggerOperation attribute is used to specify the operation ID and summary for a controller action. It is used to generate Swagger documentation for the API.
105. What is the purpose of the SwaggerResponse attribute in ASP.NET Web API?
Ans: The SwaggerResponse attribute is used to specify the response type and description for a controller action. It is used to generate Swagger documentation for the API.
106. What is the purpose of the SwaggerTag attribute in ASP.NET Web API?
Ans: The SwaggerTag attribute is used to specify the tag name and description for a controller action. It is used to generate Swagger documentation for the API.
107. What is the purpose of the ApiExplorerSettings attribute in ASP.NET Web API?
Ans: The ApiExplorerSettings attribute is used to configure the settings for the API Explorer in ASP.NET Web API. It specifies the route prefix and other settings for the API Explorer.
108. What is the purpose of the ApiController attribute in ASP.NET Web API?
Ans: The ApiController attribute is used to indicate that a controller is an API controller. It can be used to configure global settings for API controllers, such as route prefixes and authorization filters.
109. What is the purpose of the HttpGet and HttpPost attributes in ASP.NET Web API?
Ans: The HttpGet and HttpPost attributes are used to specify that a controller action should respond to HTTP GET and POST requests, respectively.
110. What is the purpose of the FromBody attribute in ASP.NET Web API?
Ans: The FromBody attribute is used to indicate that a parameter should be bound from the body of the HTTP request.
111. What is the purpose of the FromQuery attribute in ASP.NET Web API?
Ans: The FromQuery attribute is used to indicate that a parameter should be bound from the query string of the HTTP request.
112. What is the purpose of the FromRoute attribute in ASP.NET Web API?
Ans: The FromRoute attribute is used to indicate that a parameter should be bound from the route data of the HTTP request.
113. What is the purpose of the FromHeader attribute in ASP.NET Web API?
Ans: The FromHeader attribute is used to indicate that a parameter should be bound from the header of the HTTP request.
114. What is the purpose of the FromForm attribute in ASP.NET Web API?
Ans: The FromForm attribute is used to indicate that a parameter should be bound from the form data of the HTTP request.
115. What is the purpose of the FromServices attribute in ASP.NET Web API?
Ans: The FromServices attribute is used to indicate that a parameter should be bound from a registered service in the dependency injection container.
116. What is the purpose of the Produces attribute in ASP.NET Web API?
Ans: The Produces attribute is used to specify that an action method returns a specific HTTP status code. It is used to indicate the expected outcome of an action.
117. What is the purpose of the Consumes attribute in ASP.NET Web API?
Ans: The Consumes attribute is used to specify that an action method consumes a specific HTTP status code. It is used to indicate the expected input of an action.
118. What is the purpose of the HttpResponseMessage attribute in ASP.NET Web API?
Ans: The HttpResponseMessage attribute is used to specify that an action method returns a specific HTTP status code and message. It is used to indicate the expected outcome of an action.
119. What is the purpose of the Authorize attribute in ASP.NET Web API?
Ans: The Authorize attribute is used to specify the authorization policy for a controller or action. It is used to restrict access to specific users or roles.
120. What is the purpose of the EnableCors attribute in ASP.NET Web API?
Ans: The EnableCors attribute is used to enable Cross-Origin Resource Sharing (CORS) for a controller or action. It allows the API to be accessed from different origins.
121. What is the purpose of the SwaggerOperation attribute in ASP.NET Web API?
Ans: The SwaggerOperation attribute is used to specify the operation ID and summary for a controller action. It is used to generate Swagger documentation for the API.
122. What is the purpose of the SwaggerResponse attribute in ASP.NET Web API?
Ans: The SwaggerResponse attribute is used to specify the response type and description for a controller action. It is used to generate Swagger documentation for the API.
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