POST for creating resources in Rest API - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the HTTP status code returned after a successful POST request?

Consider a REST API where you send a POST request to create a new user. The server successfully creates the user and returns a response.

What is the typical HTTP status code you expect in the response?

A 200 OK

B 404 Not Found

C 500 Internal Server Error

D 201 Created

💡 Hint

Think about the status code that indicates a new resource was successfully created.

201 Created is the standard status code returned when a POST request successfully creates a new resource.

❓ Predict Output

intermediate

What is the response body after creating a resource with POST?

You send a POST request to create a new book resource. The server responds with JSON containing the new book's ID and title.

What is the expected JSON response body?

Rest API

POST /books HTTP/1.1
Host: example.com
Content-Type: application/json

{"title": "Learn REST"}

A {"id": 101, "title": "Learn REST"}

B {"error": "Missing title"}

C {"status": "success"}

D {}

💡 Hint

The server usually returns the created resource with its new ID.

After creating a resource, the server often returns the full resource including its new unique ID.

🔧 Debug

advanced

Why does this POST request return 400 Bad Request?

Examine the following POST request code snippet. It tries to create a new user but the server returns a 400 Bad Request error.

POST /users HTTP/1.1
Host: api.example.com
Content-Type: application/json

{"username": "", "email": "[e-mail]"}

What is the most likely cause of the 400 error?

A The email field is missing

B The Content-Type header is missing

C The username field is empty, violating validation rules

D The HTTP method should be GET instead of POST

💡 Hint

Check the data sent in the request body for required fields.

A 400 Bad Request often means the server rejected the input data. An empty username likely violates validation rules.

🧠 Conceptual

advanced

Which header is important to include in a POST request with JSON data?

When sending a POST request with JSON data to create a resource, which HTTP header must you include to inform the server about the data format?

A Content-Type

B Authorization

C Accept-Encoding

D Cache-Control

💡 Hint

This header tells the server what format the request body is in.

The Content-Type header specifies the media type of the request body, such as application/json.

❓ Predict Output

expert

What is the value of the Location header after a successful POST?

A POST request creates a new resource at the server. The server responds with status 201 Created and includes a Location header.

What does the Location header contain?

A The URL of the POST endpoint

B The URL of the newly created resource

C The client's IP address

D The server's root URL

💡 Hint

The Location header tells the client where to find the new resource.

The Location header contains the URL of the newly created resource so the client can access it directly.