Why HTTP methods define API intent in Postman - Challenge Your Understanding

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding HTTP Methods and API Intent

Which HTTP method is typically used to update an existing resource in a RESTful API?

A PUT

B GET

C POST

D DELETE

💡 Hint

Think about which method replaces or modifies a resource completely.

The PUT method is used to update or replace an existing resource. GET is for retrieving data, POST is for creating new resources, and DELETE removes resources.

❓ Predict Output

intermediate

HTTP Method Effect on API Response

What will be the HTTP status code returned when a POST request successfully creates a new resource?

A 200 OK

B 404 Not Found

C 204 No Content

D 201 Created

💡 Hint

Successful creation usually returns a specific status code indicating resource creation.

201 Created indicates that the request has succeeded and a new resource has been created as a result.

❓ assertion

advanced

Correct Assertion for DELETE Method

In Postman, which assertion correctly verifies that a DELETE request was successful by checking the status code?

Postman

pm.test('Status code is 204', () => {
    pm.response.to.have.status(204);
});

A pm.test('Status code is 200', () => { pm.response.to.have.status(200); });

B pm.test('Status code is 204', () => { pm.response.to.have.status(204); });

C pm.test('Status code is 404', () => { pm.response.to.have.status(404); });

D pm.test('Status code is 201', () => { pm.response.to.have.status(201); });

💡 Hint

DELETE success usually returns a status code indicating no content.

204 No Content is the standard response for a successful DELETE request indicating the resource was deleted and no content is returned.

🔧 Debug

advanced

Debugging Incorrect HTTP Method Usage

A tester sends a GET request to an API endpoint that only supports POST. The response is 405 Method Not Allowed. What is the most likely cause?

A The request body is missing.

B The API endpoint does not exist.

C The HTTP method used is not supported by the endpoint.

D The server is down.

💡 Hint

405 status means the method is not allowed on the resource.

405 Method Not Allowed means the HTTP method used is not supported by the endpoint. Using GET instead of POST causes this error.

❓ framework

expert

Designing Tests for API Intent Using HTTP Methods

Which test case best verifies that an API correctly implements the intent of the PATCH HTTP method?

A Send a PATCH request with partial data and verify only specified fields are updated.

B Send a PATCH request with full data and verify the entire resource is replaced.

C Send a DELETE request and verify the resource is removed.

D Send a GET request and verify the resource is unchanged.

💡 Hint

PATCH is used for partial updates, not full replacements.

PATCH requests are intended to partially update a resource. The test should verify that only the specified fields change, not the entire resource.

Practice

1. Which HTTP method is typically used to retrieve data from an API without changing any data?

easy

A. PUT

B. GET

C. DELETE

D. POST

Solution

1. Step 1: Understand the purpose of HTTP methods

   GET is used to request data without modifying it, making it safe and idempotent.

2. Step 2: Match method to action

   Since the question asks for retrieving data without changes, GET fits perfectly.

3. Final Answer:

   GET -> Option B

4. Quick Check:

   Retrieve data = GET [OK]

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

Common Mistakes:

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

2. Which of the following is the correct syntax to send data to create a new resource using Postman?

easy

A. Use GET method with a request body

B. Use PUT method without a request body

C. Use DELETE method with a request body

D. Use POST method with a request body

Solution

1. Step 1: Identify method for creating resources

   POST is the standard HTTP method to create new resources and it requires a request body with data.

2. Step 2: Check syntax correctness

   GET should not have a body, DELETE is for removing, and PUT usually updates or replaces resources with a body.

3. Final Answer:

   Use POST method with a request body -> Option D

4. Quick Check:

   Create resource = POST + body [OK]

Hint: POST creates with data in body, GET never has body [OK]

Common Mistakes:

• Trying to send body with GET method
• Using DELETE to create data
• Assuming PUT never needs a body

3. Consider this Postman request using PUT method to update a user profile. What is the expected behavior?

medium

A. It replaces the entire user profile with the provided data.

B. It partially updates the user profile fields.

C. It creates a new user if the user ID does not exist.

D. It deletes the user profile.

Solution

1. Step 1: Understand the PUT method intent

   PUT is used to replace the entire resource at the given URL with the data sent in the request.

2. Step 2: Differentiate from PATCH and DELETE

   PATCH partially updates, DELETE removes, and PUT replaces fully or creates if missing.

3. Final Answer:

   It replaces the entire user profile with the provided data. -> Option A

4. Quick Check:

   PUT = full replace [OK]

Hint: PUT replaces whole resource, PATCH updates parts [OK]

Common Mistakes:

• Confusing PUT with PATCH for partial updates
• Thinking PUT deletes data
• Assuming PUT never creates new resource

4. You sent a PATCH request in Postman to update a user's email, but the entire user data was overwritten instead. What is the likely cause?

medium

A. The server treats PATCH like PUT and replaces the whole resource.

B. PATCH requests cannot update email fields.

C. You used GET method instead of PATCH.

D. The request body was empty.

Solution

1. Step 1: Understand PATCH vs PUT behavior

   PATCH is meant for partial updates, but some servers treat PATCH like PUT and replace the entire resource.

2. Step 2: Analyze the problem

   Since the entire data was overwritten, the server likely did not handle PATCH correctly and replaced the resource.

3. Final Answer:

   The server treats PATCH like PUT and replaces the whole resource. -> Option A

4. Quick Check:

   Server misinterprets PATCH as PUT [OK]

Hint: Server may treat PATCH as full replace (PUT) [OK]

Common Mistakes:

• Assuming PATCH cannot update specific fields
• Confusing PATCH with GET method
• Ignoring empty request body possibility

5. You want to design an API endpoint in Postman that safely deletes a user but only if the user exists. Which HTTP method and response status code combination best defines this intent?

hard

A. Use GET method and return 204 No Content

B. Use POST method and return 200 OK always

C. Use DELETE method and return 404 Not Found if user missing

D. Use PUT method and return 201 Created

Solution

1. Step 1: Choose correct HTTP method for deletion

   DELETE is the standard method to remove resources safely.

2. Step 2: Select appropriate response code for missing resource

   If the user does not exist, returning 404 Not Found clearly informs the client.

3. Final Answer:

   Use DELETE method and return 404 Not Found if user missing -> Option C

4. Quick Check:

   Delete + 404 if missing = safe API [OK]

Hint: DELETE removes; 404 means resource not found [OK]

Common Mistakes:

• Using POST to delete resources
• Returning 200 OK even if user missing
• Using GET or PUT incorrectly for deletion