REST API design for systems in HLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the HTTP method used to retrieve data in REST API design.

HLD

To fetch data from a REST API, the client sends a [1] request.

Drag options to blanks, or click blank then click option'

APOST

BDELETE

CPUT

DGET

Attempts:

3 left

💡 Hint

Common Mistakes

Using POST instead of GET to retrieve data.

Confusing GET with DELETE or PUT methods.

The GET method is used to retrieve data from a server without modifying it.

2fill in blank

medium

Complete the code to define the correct status code for a successful resource creation in REST API.

HLD

When a new resource is created successfully, the server responds with status code [1].

Drag options to blanks, or click blank then click option'

A201

B200

C404

D500

Attempts:

3 left

💡 Hint

Common Mistakes

Using 200 instead of 201 for creation.

Confusing 404 (Not Found) with success codes.

Status code 201 means 'Created', indicating the resource was successfully created.

3fill in blank

hard

Fix the error in the REST API endpoint path to follow best practices for resource naming.

HLD

The incorrect endpoint path is: '/getUserDetails/[1]'. Correct it to a RESTful style.

Drag options to blanks, or click blank then click option'

A/getUserDetails/{{BLANK_1}}

B/users/{{BLANK_1}}

C/user-details/{{BLANK_1}}

D/userDetails/get/{{BLANK_1}}

Attempts:

3 left

💡 Hint

Common Mistakes

Including verbs like 'get' in the endpoint path.

Using singular nouns inconsistently.

RESTful APIs use plural nouns for resource names, so '/users/{id}' is correct.

4fill in blank

hard

Fill both blanks to complete the REST API design for updating a resource using the correct HTTP method and status code.

HLD

To update a resource, the client sends a [1] request, and the server responds with status code [2] if successful.

Drag options to blanks, or click blank then click option'

APUT

BPATCH

C200

D204

Attempts:

3 left

💡 Hint

Common Mistakes

Using PATCH instead of PUT for full updates.

Using 204 when content is expected in response.

PUT is used to update a resource fully, and 200 means the update was successful with content returned.

5fill in blank

hard

Fill all three blanks to complete the REST API design snippet for deleting a resource, including HTTP method, endpoint path, and expected status code.

HLD

The client sends a [1] request to '[2]/[3]' to delete a resource, and the server responds with status code 204.

Drag options to blanks, or click blank then click option'

ADELETE

Busers

C123

DGET

Attempts:

3 left

💡 Hint

Common Mistakes

Using GET instead of DELETE to remove resources.

Omitting the resource ID in the path.

DELETE method is used to remove a resource at '/users/123'. Status 204 means success with no content returned.

Practice

1. Which HTTP method is typically used to retrieve data from a REST API without modifying it?

easy

A. DELETE

B. POST

C. GET

D. PUT

Solution

1. Step 1: Understand HTTP methods in REST

   GET is used to request data without changing the server state.

2. Step 2: Match method to action

   POST creates or modifies data, PUT updates, DELETE removes data.

3. Final Answer:

   GET -> Option C

4. Quick Check:

   Retrieve data = GET [OK]

Hint: GET is for reading data only, no changes [OK]

Common Mistakes:

• Confusing POST with GET
• Using PUT for data retrieval
• Thinking DELETE retrieves data

2. Which of the following is the correct URL format to access a specific user with ID 123 in a REST API?

easy

A. /users/123

B. /users/getUser?id=123

C. /getUser/123

D. /users?id=123

Solution

1. Step 1: Identify RESTful URL design

   REST URLs use resource names and IDs as path segments, not actions or query for specific resource.

2. Step 2: Compare options

   /users/123 correctly points to user resource with ID 123; others use verbs or query parameters incorrectly.

3. Final Answer:

   /users/123 -> Option A

4. Quick Check:

   Resource ID in path = /users/123 [OK]

Hint: Use resource path + ID, avoid verbs in URL [OK]

Common Mistakes:

• Using verbs like getUser in URL
• Using query params for resource ID
• Mixing action names with resource paths

3. Given the following REST API call: DELETE /orders/456, what is the expected outcome?

medium

A. It deletes order 456 from the system

B. It updates order 456's status

C. It retrieves order 456's details

D. It creates a new order with ID 456

Solution

1. Step 1: Understand HTTP DELETE method

   DELETE is used to remove a resource identified by the URL.

2. Step 2: Analyze the URL and method

   /orders/456 points to order with ID 456; DELETE removes it.

3. Final Answer:

   It deletes order 456 from the system -> Option A

4. Quick Check:

   DELETE + resource ID = delete resource [OK]

Hint: DELETE method removes resource at given URL [OK]

Common Mistakes:

• Thinking DELETE retrieves data
• Confusing DELETE with POST
• Assuming DELETE creates or updates

4. A developer designed a REST API endpoint as POST /users/123/updateEmail to update a user's email. What is the main issue with this design?

medium

A. Using POST instead of GET for update

B. Including action 'updateEmail' in the URL violates REST principles

C. Missing user ID in the URL

D. Using query parameters instead of path variables

Solution

1. Step 1: Review REST URL design principles

   REST APIs should use resource paths, not actions in URLs.

2. Step 2: Identify the problem in the URL

   Including 'updateEmail' is an action, which breaks REST design; updates should use PUT or PATCH on /users/123.

3. Final Answer:

   Including action 'updateEmail' in the URL violates REST principles -> Option B

4. Quick Check:

   URLs represent resources, not actions [OK]

Hint: Avoid verbs in URLs; use HTTP methods for actions [OK]

Common Mistakes:

• Using verbs in URL paths
• Confusing POST with GET for updates
• Omitting resource IDs

5. You need to design a REST API for a system managing books and their authors. Which design best follows REST principles for retrieving all books by a specific author with ID 789?

hard

A. /books/authors/789

B. /books?author=789

C. /getBooksByAuthor/789

D. /authors/789/books

Solution

1. Step 1: Understand resource hierarchy in REST

   Authors and books are resources; books by an author are a sub-resource of author.

2. Step 2: Evaluate URL options

   /authors/789/books clearly shows books belonging to author 789, following REST resource nesting.

3. Step 3: Consider query vs path

   While query parameters can filter, nested resource path is more RESTful for related resources.

4. Final Answer:

   /authors/789/books -> Option D

5. Quick Check:

   Nested resource path shows relationship [OK]

Hint: Use nested paths for related resources [OK]

Common Mistakes:

• Using verbs in URL
• Overusing query parameters
• Ignoring resource relationships