When you go for an interview that involves REST API, you want to make sure you are fully prepared. Here are a list of common REST API Interview Questions & unique answers to the same.
REST APIs are a key component in many modern web applications. They allow developers to create services that can be consumed by other software programs. This article will cover some of the most commonly asked REST API interview questions. We hope it helps you prepare for your next job interview!
An HTTP API is a set of rules used to communicate with a server. It's a standard protocol that allows computers to talk to each other. A REST API is one type of HTTP API. REST stands for Representational State Transfer. It's a method of communicating between two different systems.
There are several reasons why you might choose to use a RESTful API instead of a SOAP API. First, RESTful APIs are easier to implement than SOAP APIs because there are fewer steps involved. Second, RESTful APIs are more scalable than SOAP APIs because they're stateless. Third, RESTful APIs are simpler to understand than SOAP APIs because RESTful APIs are based on HTTP methods. Finally, RESTful APIs are better suited for mobile applications because they're easy to integrate into an app.
REST APIs typically return data as either JSON (JavaScript Object Notation) or XML (Extensible Markup Language). Both formats are text documents that contain structured data. However, JSON is much smaller than XML. Also, JSON is designed to be easily parsed by JavaScript programs. On the other hand, XML is designed to be human readable.
A GET request returns only one piece of data. This means that the response will not contain any links to additional data. A POST request returns multiple pieces of data. This means the response will contain links to additional data.
REST APIs are based on HTTP requests and responses. They use the same verbs as other web services (GET, PUT, DELETE) and follow the same rules for how to format the data returned. REST APIs are also stateless, meaning that each request is independent of previous ones. SOAP APIs are based on XML messages. They use different verbs than HTTP requests and return structured data. SOAP APIs are usually used by applications that need to exchange large amounts of data between systems.
Can you explain what a REST API is and why it is important?
How is a REST API different from a SOAP API?
Can you provide an example of a REST API request and response?
What are the principles of REST and how do they apply to API design?
What is HATEOAS and why is it important in the context of REST APIs?
Can you describe the process of requesting and retrieving data from a REST API?
What are the common HTTP methods used in REST API requests, and what do they represent?
Can you explain the difference between a resource and an endpoint in the context of a REST API?
How do you handle authentication and authorization in a REST API?
REST or REST API is an acronym which stands for Representational State Transfer. Any software architecture expert know that it is an interface between physically separate components in a client server architecture. Meaning it sits right in the middle of the of the web application & web server. It is significant because it is the channel between the web application & server & connects the two.
SOAP or SOAP API stands for Simple Object Access Protocol. The major point of difference is the technology itself. REST is a type of architecture style. A SOAP as the name suggests is a protocol or set of rules. Given the nature of the technology, a SOAP API is more stringent while a REST API is casual. For example, SOAP API uses only XML data format while REST uses XML, JSON, HTML.
Also, a SOAP API is function driven while REST is data driven. For example, when a SOAP API exhibits a function “Create User”, it has the entire code written in the body. On the contrary, a REST API will use a method “Create User” which helps you create a user account.
This is one of the common REST API Interview Questions. REST API has four major principles or constraints
It should follow a client server architecture. The data request should be clearly separated from user interface.
It should be stateless meaning each request should be unique and it should have no reinforced leaning. There should be no data related to the client on the server. Every request should be unique with no reference to any previous request.
The process should be non-transparent or layered. It should not appear to the client that he is directly talking to the server.
(This is another popular one from the list of REST API Interview Questions; What is HATEOAS and why is it important in the context of REST APIs?)
To understand the difference, let us the understand the components of a REST API request
1.Endpoint which usually means the starting or end point in any communication. In REST API an endpoint is URL at the Server Side. The endpoint contains an URI
2.HTTP Methods which the REST API implements. One of them is POST: which creates resource to the server. Other methods are
GET – to retrieve a resource
PATCH – to update a resource
PUT - to modify a resource
DELETE – to delete a resource
(This is another popular one from the list of REST API Interview Questions; What are the common HTTP methods used in REST API requests, and what do they represent?)
Request: host/ IP of client, language & data about user agent (client, OS & vendor
Response: status of request or HTTP code, type of resource, sets cookies by server)
To obtain access to the resource, the client will send an HTTP request & receive an HTTP response. A resource is any content (text file or video file) that the server can provide to the client. So, this the major point of difference between an endpoint & resource.
Let us take a diagrammatic approach from O’Reilly’s book for what happens when a customer places an order for coffee from the website of a coffee shop. This is self-descriptive. This also answers one other popular REST API Interview Questions; Can you describe the process of requesting and retrieving data from a REST API?)
These are two very popular REST API Interview Questions. This is customised. Every developer will have his own style & can make his own SOP.
