HTTP u0026 REST Fundamentals for Mobile and Wireless Clients Quiz

Explore key concepts of HTTP and REST fundamentals tailored for mobile and wireless client environments. This quiz covers methods, status codes, best practices, and challenges relevant to optimizing mobile interactions with web services.

1. Identifying RESTful Methods

   Which HTTP method is commonly used by mobile clients to retrieve data from a RESTful API, such as fetching a user profile?

   1. PUT
   2. POST
   3. DELETE
   4. GET

   Explanation: The GET method is used to request and retrieve data without modifying any resources, making it ideal for fetching information like a user profile. POST is intended for creating new resources, PUT is for updating existing data, and DELETE removes resources. Using POST, PUT, or DELETE instead of GET for simple retrieval would violate RESTful conventions and could cause unintended effects.

2. Interpreting HTTP Status Codes

   When a mobile application submits a POST request to create a new resource and receives a 201 status code, what does this status indicate?

   1. A syntax error occurred
   2. The resource was not found
   3. The resource was created successfully
   4. Authentication is required

   Explanation: A 201 status code means the resource has been created successfully as a result of the POST request. A syntax error would trigger a 400 status, not 201. A ‘not found’ scenario leads to a 404 status, while missing authentication results in a 401 response. Therefore, 201 is specifically reserved for confirming successful creation.

3. Choosing Efficient Payload Formats

   For mobile devices with limited bandwidth, which data format is generally preferred for RESTful API responses due to its lightweight nature?

   1. JSON
   2. XML
   3. YAML
   4. CSV

   Explanation: JSON is preferred because it is compact, efficient for data transfer, and widely supported by mobile platforms. XML is more verbose and increases payload size, which is a disadvantage for constrained networks. YAML is readable but less commonly used in APIs, and CSV, while lightweight, is not ideal for handling nested data structures typical in APIs.

4. Understanding Statelessness in REST

   Why is it important for mobile clients that RESTful APIs are stateless, especially over unreliable wireless connections?

   1. It increases code complexity
   2. It allows persistent connections by default
   3. It reduces battery consumption directly
   4. Each request contains all necessary information

   Explanation: Statelessness in REST means every client request includes all the data required for processing, which helps recovery from dropped connections and inconsistent network states common in wireless environments. Stateless APIs do not directly reduce battery usage. They actually minimize code complexity, not increase it, and do not entail persistent connections by default.

5. Handling Slow Networks

   Which technique helps mobile and wireless clients improve perceived performance when REST API responses are slow due to poor network conditions?

   1. Disabling HTTP headers
   2. Increasing request payload size
   3. Using only synchronous requests
   4. Caching frequently requested data

   Explanation: Caching allows clients to locally store and reuse previously retrieved data, leading to faster responses on repeated requests even in slow network conditions. Disabling HTTP headers removes necessary metadata but does not improve speed. Synchronous requests can block the user interface, worsening the user experience. Increasing payload size further worsens performance on limited networks.