Landing your dream job in the tech world often hinges on acing your interview. And when it comes to HTTP being prepared with the right answers can make all the difference.
This comprehensive guide dives deep into the top 20+ HTTP interview questions equipping you with the knowledge and confidence to impress your interviewer and secure that coveted position.
1. What’s the deal with HTTP?
HTTP, short for Hypertext Transfer Protocol, is the backbone of the World Wide Web. It’s the set of rules that governs how files like audio, video, images, and text are transferred across the internet. Think of it as the language spoken between your web browser and the servers that host websites.
2 Decoding HTTP Request Messages
These messages are sent by the client (your browser) to initiate an action on the server. They’re like little notes containing instructions and they consist of several key parts
- Request Line: This is where the action (GET, POST, etc.) is specified, along with the target resource (the URL) and the protocol version.
- Resource Identifier: This pinpoints the exact file or data the client wants.
- Request Header Fields: These provide additional information about the client and the request, like the type of data being requested.
3 HTTP Request Methods Your Toolbox of Actions
These methods define what the client wants to do with the resource. Here are some of the most common ones:
- GET: Retrieves information from the server.
- HEAD: Similar to GET, but only retrieves the header information, not the actual content.
- POST: Sends data to the server, often used for submitting forms.
- PUT: Replaces the existing resource with new content.
- DELETE: Removes the specified resource.
4. Status Codes: The Server’s Response Language
The server responds to client requests with status codes, which are three-digit numbers. The first digit indicates the general category of the response (e.g., success, error), while the last two provide more specific information.
5. Persistent Connections: Keeping the Conversation Going
In HTTP/1.0, each request-response pair required a new connection. HTTP/1.1 introduced “keep-alive” connections, allowing multiple requests over a single connection, improving efficiency.
6. Stateless or Stateful? HTTP’s Memory
HTTP is stateless, meaning the server doesn’t remember past interactions with the client. Each request is treated as a fresh start. This can be both a security advantage and a challenge for managing user sessions.
7. HTTP Messages: The Backbone of Communication
These messages are the foundation of client-server communication. The client sends a request message, and the server responds with a response message. Both messages follow a specific format, ensuring smooth data exchange.
8. HTTP cURL: Your Command-Line Power Tool
cURL is a versatile command-line tool that lets you interact with HTTP servers directly. It’s a handy tool for testing requests, debugging, and automating tasks.
9. HTTP Response: The Server’s Reply
This message contains the server’s response to the client’s request. It includes the status code, header fields with additional information, and the actual response body (the content).
10. HTTP Security: Protecting Your Data in Transit
HTTP communication can be vulnerable to eavesdropping and attacks. To ensure secure data transfer, HTTPS uses encryption and other security measures.
11. 200 OK: The Green Light for Success
This status code indicates that the client’s request was successful, and the server has delivered the requested resource.
12. 201 Created: A New Addition to the World Wide Web
This code signifies that the server successfully created a new resource as a result of the client’s request.
13. 300 Multiple Choices: When You’re Spoiled for Options
This code indicates that the resource requested by the client has multiple possible representations, and the client can choose which one to access.
14. 400 Bad Request: When Things Go Wrong
This code tells the client that the server couldn’t understand the request due to invalid syntax or formatting.
15. 401 Unauthorized: Access Denied
This code indicates that the client needs to provide authentication credentials (like a username and password) before accessing the resource.
16. 405 Method Not Allowed: The Wrong Tool for the Job
This code tells the client that the requested method (e.g., GET, POST) is not supported for the specified resource.
17. 408 Request Timeout: Time’s Up
This code indicates that the server didn’t receive the client’s request within the expected timeframe.
18. 500 Internal Server Error: Something Went Wrong
This code signals that the server encountered an unexpected error and couldn’t fulfill the client’s request.
19. IP’s Home in the OSI Model
IP (Internet Protocol) resides in the Network layer of the OSI model, which is the third layer responsible for routing data packets across networks.
20. HTTP’s Many Roles: More Than Just a Fetching Tool
HTTP was initially designed to fetch HTML documents, but it has evolved into a versatile protocol for various tasks, including data transfer, API communication, and web services.
21. HTTPS: Adding Security to the Mix
HTTPS (Hypertext Transfer Protocol Secure) encrypts communication between the client and server, providing an extra layer of security for sensitive data.
22. Content Negotiation: Finding the Perfect Fit
When a server has multiple representations of a resource (e.g., different file formats), content negotiation helps determine the best version for the client based on its preferences and capabilities.
23. Types of Content Negotiation: Server, Agent, and the Hybrid Approach
- Server-driven Negotiation: The server selects the best representation based on its algorithms.
- Agent-driven Negotiation: The client chooses the best representation after receiving an initial response from the server.
- Transparent Negotiation: A combination of both server-driven and agent-driven approaches.
24. 100 Continue: A Nod of Approval
This code indicates that the server has received the initial part of the client’s request and is ready for the rest.
Bonus Tip: Stay up-to-date with the latest HTTP advancements and security best practices to demonstrate your knowledge and commitment to the field.
By mastering these HTTP interview questions and concepts, you’ll be well-equipped to impress your interviewer and land your dream job in the exciting world of web development. Remember, confidence, clear communication, and a passion for technology will further enhance your chances of success.
What is the difference between a URL and a URI?
The difference between a URL and a URI is that a URL is a specific type of URI. If you want to find a name or resource on the Internet, you can use a Uniform Resource Identifier (URI). It can be further classified into two types: Uniform Resource Locator (URL) and Uniform Resource Name (URN). A URL is a specific type of URI that specifies the location of a resource on the Internet. It helps you find web pages, videos, and other files that are stored on a web server. A URL typically consists of the protocol used to access the resource (e. g. http or https), the domain name or IP address of the server, and the path to the resource. For example, http://www. example. com/index. html is a URL that points to the index. html page on the example. com website. A URN, on the other hand, is a type of URI that is used to find a resource by name instead of where it is. People usually use it to find books, articles, documents, and other resources that aren’t on the Internet. For example, urn:isbn:978-1-56619-909-4 is a URN that identifies a book by its ISBN number.
Describe the HTTP request/response cycle and explain how it works.
The HTTP request/response cycle is the process by which a client (e. g. a web browser) sends an HTTP request to a server and the server responds with an HTTP response. This cycle is the foundation of how the web works and is essential for web developers to understand. The cycle begins when the client sends an HTTP request to the server. This request contains information about the type of request being made (e. g. GET, POST, PUT, etc. ), the resource’s URL, and any other information that might be needed for the request (e.g. g. form data). Once the server receives the request, it processes the request and generates an HTTP response. This response contains information about the status of the request (e. g. success or failure), the type of content being returned (e. g. HTML, JSON, etc. ), and any additional data that may be necessary for the response (e. g. the requested resource). The client then receives the response and processes it accordingly. If the response is successful, the client will display the requested resource. If the response is unsuccessful, the client will display an error message. The cycle then repeats as the client sends additional requests and the server responds with additional responses. This cycle is the basis for how the web works and is essential for web developers to understand.
REST API Interview Questions (Advanced Level)
FAQ
How do you explain REST API in an interview?
What markup language is used in REST API?
What is the difference between REST and soap interview questions?
What are http interview questions?
HTTP interview questions help interviewers check your knowledge of the internet protocol suite, HTTP use case and methods when you apply for a network administrator or system administrator job. The interviewer often asks about the use cases, methods and error codes of HTTP to analyse your level of understanding.
What questions should you ask during an HTTP protocol interview?
Here are 20 commonly asked HTTP Protocol interview questions and answers to prepare you for your interview: 1. What is HTTP? HTTP is the protocol that governs communication between web servers and clients. It is the foundation of the World Wide Web. 2. How does the HTTP protocol work? The HTTP protocol is a request-response protocol.
What is the difference between put and post method?
PUT methods are used to request the server to store the enclosed entity in request. In case, the request does not exist, then new resource has to be created. If the resource exists, then the resource should get updated. POST method is used to request the server to store the enclosed entity in the request as a new resource.
What are HTTP methods?
The HTTP protocol defines a set of methods, or verbs, that the client can use to request a resource from the server. The most common methods are GET, which requests a resource from the server, and POST, which submits data to the server. 3. What does REST stand for and what are its associated principles?
