MCQs On Class 29: Working with APIs - Part 1
Here’s a set of 100 multiple-choice questions (MCQs) related to APIs, PHP, and web development concepts. Each question has four options, with the correct answer indicated.
Multiple Choice Questions (MCQs)
1. What does API stand for?
a) Application Programming Interface
b) Advanced Programming Interface
c) Application Protocol Interface
d) Automated Programming Interface
Answer: a) Application Programming Interface
2. Which of the following is a common protocol used for APIs?
a) FTP
b) HTTP
c) SMTP
d) POP3
Answer: b) HTTP
3. What type of API uses the REST architecture?
a) SOAP
b) JSON-RPC
c) RESTful API
d) XML-RPC
Answer: c) RESTful API
4. Which HTTP method is typically used to retrieve data from an API?
a) POST
b) GET
c) PUT
d) DELETE
Answer: b) GET
5. Which function in PHP is used to decode a JSON string?
a) json_parse()
b) json_decode()
c) json_stringify()
d) json_convert()
Answer: b) json_decode()
6. Which PHP library is commonly used to make HTTP requests?
a) MySQLi
b) cURL
c) PDO
d) OpenSSL
Answer: b) cURL
7. What status code indicates a successful HTTP request?
a) 200
b) 404
c) 500
d) 301
Answer: a) 200
8. What does the curl_setopt() function do in PHP?
a) Executes a cURL session
b) Initializes a cURL session
c) Sets options for a cURL session
d) Closes a cURL session
Answer: c) Sets options for a cURL session
9. What is the main format for data exchange in APIs?
a) XML
b) CSV
c) JSON
d) HTML
Answer: c) JSON
10. What does a 404 status code signify?
a) Success
b) Not Found
c) Unauthorized
d) Server Error
Answer: b) Not Found
11. Which method is used to send data to an API?
a) GET
b) POST
c) PATCH
d) PUT
Answer: b) POST
12. What is the purpose of query parameters in a URL?
a) To send additional data
b) To specify the API version
c) To authenticate the request
d) To define the HTTP method
Answer: a) To send additional data
13. In a RESTful API, which method is typically used to update existing resources?
a) GET
b) POST
c) PUT
d) DELETE
Answer: c) PUT
14. What is a common use case for a public API?
a) User authentication
b) Database management
c) Weather data retrieval
d) File storage
Answer: c) Weather data retrieval
15. Which function is used to encode data to JSON in PHP?
a) json_encode()
b) json_stringify()
c) json_format()
d) json_convert()
Answer: a) json_encode()
16. What does the acronym CRUD stand for?
a) Create, Read, Update, Delete
b) Create, Read, Upload, Delete
c) Create, Review, Update, Delete
d) Create, Run, Update, Delete
Answer: a) Create, Read, Update, Delete
17. What is an endpoint in the context of APIs?
a) The server hosting the API
b) A specific URL for accessing a resource
c) A data format for API responses
d) A security measure for API calls
Answer: b) A specific URL for accessing a resource
18. What is the purpose of the curl_exec() function?
a) To set cURL options
b) To initialize a cURL session
c) To execute a cURL session and fetch data
d) To close a cURL session
Answer: c) To execute a cURL session and fetch data
19. In a RESTful API, which method would you use to delete a resource?
a) GET
b) POST
c) PUT
d) DELETE
Answer: d) DELETE
20. What does the Content-Type header specify in an HTTP request?
a) The type of request being made
b) The format of the request body
c) The encoding of the request
d) The server's response format
Answer: b) The format of the request body
21. Which of the following is NOT a valid HTTP method?
a) PUT
b) GET
c) SEND
d) POST
Answer: c) SEND
22. What does a 500 status code indicate?
a) Not Found
b) Internal Server Error
c) Success
d) Unauthorized
Answer: b) Internal Server Error
23. Which function is used to initialize a cURL session in PHP?
a) curl_start()
b) curl_init()
c) curl_begin()
d) curl_open()
Answer: b) curl_init()
24. What is the purpose of the Accept header in an HTTP request?
a) To specify the data type being sent
b) To specify the format of the response expected
c) To indicate the API version
d) To authenticate the user
Answer: b) To specify the format of the response expected
25. How do you handle JSON errors in PHP?
a) Use json_error()
b) Check the response format
c) Use json_last_error()
d) Use json_decode()
Answer: c) Use json_last_error()
26. Which of the following APIs allows you to access weather data?
a) Twitter API
b) OpenWeatherMap API
c) GitHub API
d) Google Maps API
Answer: b) OpenWeatherMap API
27. What is the primary benefit of using APIs?
a) Enhanced security
b) Code reusability
c) Increased complexity
d) Faster data processing
Answer: b) Code reusability
28. What does the PUT method typically do in REST APIs?
a) Creates a new resource
b) Updates an existing resource
c) Deletes a resource
d) Retrieves data
Answer: b) Updates an existing resource
29. What is the role of API authentication?
a) To speed up API requests
b) To secure the API from unauthorized access
c) To format the response data
d) To reduce the data transfer size
Answer: b) To secure the API from unauthorized access
30. Which of the following is a popular library for making API requests in JavaScript?
a) jQuery
b) Axios
c) cURL
d) React
Answer: b) Axios
31. Which of the following data formats is commonly used with APIs?
a) XML
b) CSV
c) JSON
d) All of the above
Answer: d) All of the above
32. What does the acronym OAuth stand for?
a) Open Authorization
b) Open Access
c) Online Authorization
d) Open API
Answer: a) Open Authorization
33. Which type of API allows for asynchronous communication?
a) REST
b) SOAP
c) GraphQL
d) WebSockets
Answer: d) WebSockets
34. In which of the following scenarios would you use a POST request?
a) To fetch user details
b) To create a new user
c) To update a user's information
d) To delete a user
Answer: b) To create a new user
35. What is a common use case for the GitHub API?
a) Weather updates
b) Stock prices
c) Code repository management
d) Social media integration
Answer: c) Code repository management
36. What kind of data can APIs return?
a) Text
b) JSON
c) XML
d) All of the above
Answer: d) All of the above
37. What is an API key?
a) A string of characters used to identify an API request
b) A type of HTTP method
c) A method of data encryption
d) A unique identifier for a user
Answer: a) A string of characters used to identify an API request
38. Which HTTP status code represents a successful creation of a resource?
a) 200
b) 201
c) 202
d) 204
Answer: b) 201
39. Which header is typically used to send authentication credentials in an API request?
a) Content-Type
b) Authorization
c) Accept
d) User-Agent
Answer: b) Authorization
40. What is the purpose of rate limiting in APIs?
a) To limit the amount of data returned
b) To control the number of requests made to the API
c) To enhance security
d) To compress the response data
Answer: b) To control the number of requests made to the API
41. What does JSON stand for?
a) JavaScript Object Notation
b) JavaScript Online Notation
c) JavaScript Object Node
d) JavaScript Open Notation
Answer: a) JavaScript Object Notation
42. Which of the following best describes a WebSocket API?
a) Synchronous and request-response based
b) Asynchronous and full-duplex
c) Stateless and limited to HTTP
d) Only for server-to-client communication
Answer: b) Asynchronous and full-duplex
43. What is the purpose of the OPTIONS HTTP method?
a) To create a resource
b) To delete a resource
c) To retrieve information about the communication options
d) To update a resource
Answer: c) To retrieve information about the communication options
44. Which is a popular API documentation tool?
a) Postman
b) Swagger
c) cURL
d) Insomnia
Answer: b) Swagger
45. What does the acronym REST stand for?
a) Representational State Transfer
b) Regular State Transfer
c) Resource State Transfer
d) Relational State Transfer
Answer: a) Representational State Transfer
46. In PHP, which function is used to check for errors in JSON data?
a) json_error()
b) json_last_error()
c) json_validate()
d) json_status()
Answer: b) json_last_error()
47. Which HTTP status code is used for unauthorized access?
a) 200
b) 403
c) 401
d) 404
Answer: c) 401
48. What is the purpose of API versioning?
a) To change the API's URL
b) To improve performance
c) To ensure backward compatibility
d) To enhance security
Answer: c) To ensure backward compatibility
49. What does a 204 status code signify?
a) Resource created
b) No content
c) Resource deleted
d) Request accepted
Answer: b) No content
50. Which method would you use to fetch user data without modifying it?
a) POST
b) PUT
c) DELETE
d) GET
Answer: d) GET
51. What type of authentication is commonly used in APIs?
a) Basic authentication
b) Token-based authentication
c) OAuth
d) All of the above
Answer: d) All of the above
52. What is the purpose of the User-Agent header?
a) To identify the client making the request
b) To specify the type of content being sent
c) To authenticate the user
d) To indicate the API version
Answer: a) To identify the client making the request
53. Which of the following is a valid JSON object?
a) {name: "John", age: 30}
b) {"name": "John", "age": 30}
c) ["name": "John", "age": 30]
d) "name": "John", "age": 30
Answer: b) {"name": "John", "age": 30}
54. What is the purpose of API documentation?
a) To provide code examples
b) To explain how to use the API
c) To list the available endpoints and methods
d) All of the above
Answer: d) All of the above
55. What is a common response format for RESTful APIs?
a) HTML
b) JSON
c) XML
d) Both b and c
Answer: d) Both b and c
56. Which function in PHP is used to set HTTP headers?
a) header()
b) set_header()
c) http_header()
d) response_header()
Answer: a) header()
57. What does an API gateway do?
a) Routes requests to various microservices
b) Acts as a database
c) Generates API keys
d) Monitors API performance
Answer: a) Routes requests to various microservices
58. What is the main advantage of using REST over SOAP?
a) REST is more secure
b) REST supports multiple formats
c) REST requires more bandwidth
d) REST is less flexible
Answer: b) REST supports multiple formats
59. Which HTTP method is idempotent, meaning it can be called multiple times without different outcomes?
a) GET
b) POST
c) DELETE
d) Both a and c
Answer: d) Both a and c
60. What is the purpose of the Content-Length header in an HTTP request?
a) To specify the server's response time
b) To indicate the size of the request body
c) To define the encoding type
d) To specify the API version
Answer: b) To indicate the size of the request body
61. In the context of APIs, what does the term "endpoint" refer to?
a) A client making a request
b) A specific URL for a service
c) The data format used
d) The API documentation
Answer: b) A specific URL for a service
62. What is the role of middleware in an API?
a) To connect to the database
b) To process requests and responses
c) To handle user authentication
d) All of the above
Answer: d) All of the above
63. What does it mean when an API is "stateless"?
a) It maintains user sessions
b) It does not store client context
c) It requires authentication
d) It uses cookies
Answer: b) It does not store client context
64. What is a common feature of GraphQL?
a) Fixed endpoints
b) Single endpoint for all queries
c) Only supports JSON format
d) Requires SOAP
Answer: b) Single endpoint for all queries
65. What does the term "throttling" refer to in API management?
a) Blocking all API requests
b) Limiting the number of API requests
c) Improving API performance
d) Increasing API bandwidth
Answer: b) Limiting the number of API requests
66. Which of the following is a popular tool for testing APIs?
a) Git
b) Docker
c) Postman
d) Jenkins
Answer: c) Postman
67. In PHP, which function retrieves the HTTP request method?
a) get_request_method()
b) $_SERVER['REQUEST_METHOD']
c) request_method()
d) fetch_request_method()
Answer: b) $_SERVER['REQUEST_METHOD']
68. Which of the following is a common data format for web APIs?
a) YAML
b) JSON
c) XML
d) All of the above
Answer: d) All of the above
69. What is the purpose of using the PATCH method in REST APIs?
a) To retrieve data
b) To update part of a resource
c) To create a resource
d) To delete a resource
Answer: b) To update part of a resource
70. Which HTTP header is used to specify the accepted content types in a request?
a) Content-Type
b) Accept
c) Authorization
d) User-Agent
Answer: b) Accept
71. What is the role of an API client?
a) To serve as the database
b) To handle API requests and responses
c) To create API documentation
d) To manage user authentication
Answer: b) To handle API requests and responses
72. Which status code indicates that the request was accepted but processing is not yet complete?
a) 202
b) 200
c) 204
d) 404
Answer: a) 202
73. What is a common characteristic of SOAP APIs?
a) They are lightweight
b) They use XML for messaging
c) They are RESTful
d) They support multiple data formats
Answer: b) They use XML for messaging
74. Which of the following is NOT a common type of API?
a) Web API
b) Operating System API
c) Database API
d) User Interface API
Answer: d) User Interface API
75. What does the term "payload" refer to in an API request?
a) The URL of the API
b) The metadata of the request
c) The data sent in the request body
d) The response headers
Answer: c) The data sent in the request body
76. What is the primary advantage of using JSON over XML?
a) JSON is easier to read
b) JSON uses more bandwidth
c) JSON supports comments
d) JSON is slower to parse
Answer: a) JSON is easier to read
77. In PHP, how do you send a GET request with cURL?
a) curl_get()
b) curl_send()
c) curl_exec() with method set to GET
d) curl_request()
Answer: c) curl_exec() with method set to GET
78. What does "client-side" mean in the context of APIs?
a) The server processes the request
b) The API is used in the browser or client application
c) The API requires server authentication
d) The API is only accessible via command-line
Answer: b) The API is used in the browser or client application
79. Which of the following best describes JSONP?
a) A method for handling binary data
b) A way to bypass CORS restrictions
c) A new data format for APIs
d) An extension of JSON
Answer: b) A way to bypass CORS restrictions
80. What is the purpose of the Referer header in an HTTP request?
a) To indicate the source of the request
b) To specify content type
c) To authenticate the user
d) To provide API documentation
Answer: a) To indicate the source of the request
81. What does the term "CORS" stand for?
a) Cross-Origin Resource Sharing
b) Client-Origin Resource Sharing
c) Cross-Origin Request Security
d) Client-Origin Request Security
Answer: a) Cross-Origin Resource Sharing
82. Which status code indicates that the server could not understand the request?
a) 400
b) 401
c) 404
d) 500
Answer: a) 400
83. What is a common use case for webhooks?
a) Polling the server for updates
b) Automatically sending data from one application to another
c) Managing user authentication
d) Generating API documentation
Answer: b) Automatically sending data from one application to another
84. In PHP, what function is used to decode JSON data?
a) json_decode()
b) json_parse()
c) decode_json()
d) parse_json()
Answer: a) json_decode()
85. What does the acronym OAuth stand for?
a) Open Authentication
b) Open Authorization
c) Online Authentication
d) Online Authorization
Answer: b) Open Authorization
86. Which of the following is a common way to handle errors in APIs?
a) Using status codes
b) Sending detailed error messages
c) Logging errors
d) All of the above
Answer: d) All of the above
87. What is a common practice for securing API endpoints?
a) Using HTTPS
b) Limiting API access by IP
c) Implementing rate limiting
d) All of the above
Answer: d) All of the above
88. In the context of APIs, what does "scaling" refer to?
a) Increasing API documentation
b) Handling more requests as traffic increases
c) Changing the API version
d) Implementing new features
Answer: b) Handling more requests as traffic increases
89. What is a common use of API tokens?
a) To improve server performance
b) To authenticate API requests
c) To format API responses
d) To log API usage
Answer: b) To authenticate API requests
90. What is the role of caching in APIs?
a) To store user data
b) To reduce server load and improve response times
c) To manage authentication
d) To format responses
Answer: b) To reduce server load and improve response times
91. Which of the following best describes an API key?
a) A method of user authentication
b) A string that identifies a user or application
c) A type of access token
d) All of the above
Answer: d) All of the above
92. What does the term "latency" refer to in APIs?
a) The amount of data processed
b) The time it takes for a request to be processed
c) The speed of the server
d) The amount of bandwidth used
Answer: b) The time it takes for a request to be processed
93. Which HTTP status code indicates that the requested resource was not found?
a) 500
b) 404
c) 403
d) 200
Answer: b) 404
94. What is the main purpose of an API client library?
a) To manage server resources
b) To simplify API integration in applications
c) To store API documentation
d) To monitor API performance
Answer: b) To simplify API integration in applications
95. Which HTTP method is used to completely replace a resource?
a) POST
b) GET
c) PUT
d) PATCH
Answer: c) PUT
96. What is a common use of the DELETE method in APIs?
a) To retrieve data
b) To remove a resource
c) To update a resource
d) To create a resource
Answer: b) To remove a resource
97. In the context of API design, what does "HATEOAS" stand for?
a) Hypertext Application Transfer Protocol
b) Hypermedia as the Engine of Application State
c) Hyperlink as the Engine of Application State
d) Hypertext Application Transfer System
Answer: b) Hypermedia as the Engine of Application State
98. What is the role of the Authorization header in an HTTP request?
a) To indicate the API version
b) To provide credentials for authenticating a user
c) To specify the content type
d) To determine the request method
Answer: b) To provide credentials for authenticating a user
99. Which format is generally considered more lightweight for data exchange, JSON or XML?
a) JSON
b) XML
c) Both are equally lightweight
d) Neither is lightweight
Answer: a) JSON
100. What is the purpose of using environment variables in API development?
a) To manage user authentication
b) To store sensitive information and configuration settings
c) To generate API documentation
d) To improve performance
Answer: b) To store sensitive information and configuration settings