DELETE for removing resources in Rest API - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

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

Consider a REST API where a DELETE request is sent to remove a resource. What is the typical HTTP status code returned to indicate success?

A 204 No Content

B 201 Created

C 200 OK

D 404 Not Found

💡 Hint

Think about a response that means the resource was deleted and no content is returned.

A successful DELETE request usually returns 204 No Content, meaning the resource was deleted and there is no content to send back.

❓ Predict Output

intermediate

What happens if you DELETE a resource that does not exist?

If you send a DELETE request to remove a resource that is not found on the server, what is the typical HTTP status code returned?

A 404 Not Found

B 204 No Content

C 200 OK

D 500 Internal Server Error

💡 Hint

Think about what the server returns when the resource is missing.

If the resource does not exist, the server usually returns 404 Not Found to indicate the resource was not found.

🧠 Conceptual

advanced

Why is DELETE considered an idempotent HTTP method?

In REST APIs, DELETE is called an idempotent method. What does this mean in practice?

A DELETE requests cannot be cached

B DELETE requests always return the same status code

C Multiple DELETE requests have the same effect as one DELETE request

D DELETE requests create new resources

💡 Hint

Idempotent means repeating the action does not change the result beyond the initial application.

DELETE is idempotent because sending the same DELETE request multiple times results in the same state as sending it once. After the first successful deletion, further DELETEs do nothing.

🔧 Debug

advanced

Why does this DELETE request return 405 Method Not Allowed?

You send a DELETE request to /api/items/123 but get a 405 error. What is the most likely cause?

Rest API

DELETE /api/items/123 HTTP/1.1
Host: example.com

A The resource 123 does not exist

B The server does not support DELETE on this endpoint

C The request is missing an authentication token

D The request method should be POST instead of DELETE

💡 Hint

405 means the method is not allowed on the URL.

A 405 Method Not Allowed means the server understands the request but does not allow DELETE on that URL. The endpoint likely only supports GET or POST.

🚀 Application

expert

How to safely implement DELETE to avoid accidental data loss?

You want to implement a DELETE endpoint in your API but want to avoid accidental data loss. Which approach is best?

A Return 200 OK even if the resource does not exist

B Allow DELETE requests without any checks to keep it simple

C Delete the resource immediately without logging

D Require a confirmation token in the DELETE request body before deleting

💡 Hint

Think about adding a safety step before deleting.

Requiring a confirmation token or similar check in the DELETE request helps prevent accidental deletions by ensuring the client really intends to delete the resource.

Practice

1. What is the main purpose of the HTTP DELETE method in REST APIs?

easy

A. To remove a resource identified by a URL

B. To create a new resource on the server

C. To update an existing resource

D. To retrieve data from the server

Solution

1. Step 1: Understand HTTP methods

   HTTP methods define actions on resources. DELETE is specifically for removal.

2. Step 2: Identify DELETE's role

   DELETE removes the resource at the given URL, unlike POST (create), PUT/PATCH (update), or GET (retrieve).

3. Final Answer:

   To remove a resource identified by a URL -> Option A

4. Quick Check:

   DELETE = remove resource [OK]

Hint: DELETE always removes resource at the URL, no body needed [OK]

Common Mistakes:

• Confusing DELETE with GET or POST
• Thinking DELETE requires a request body
• Assuming DELETE creates or updates data

2. Which of the following is the correct syntax to send a DELETE request to remove a user with ID 123 using curl?

easy

A. curl -X GET https://api.example.com/users/123

B. curl -X PUT https://api.example.com/users/123

C. curl -X POST https://api.example.com/users/123

D. curl -X DELETE https://api.example.com/users/123

Solution

1. Step 1: Identify HTTP method for deletion

   DELETE method is used to remove resources, so -X DELETE is correct.

2. Step 2: Check URL and method usage

   The URL targets user 123, and curl uses -X to specify method. So, curl -X DELETE URL is correct.

3. Final Answer:

   curl -X DELETE https://api.example.com/users/123 -> Option D

4. Quick Check:

   curl DELETE syntax = curl -X DELETE URL [OK]

Hint: Use curl -X DELETE followed by resource URL [OK]

Common Mistakes:

• Using GET or POST instead of DELETE
• Omitting the -X flag for method
• Using PUT which is for updates

3. Given this Python code using requests library:

import requests
response = requests.delete('https://api.example.com/items/45')
print(response.status_code)

What will be printed if the item was successfully deleted?

medium

A. 201

B. 404

C. 200

D. 500

Solution

1. Step 1: Understand HTTP status codes for DELETE

   Successful DELETE usually returns 200 (OK) or 204 (No Content). 200 means success with response body.

2. Step 2: Check options for success code

   Among options, 200 indicates success. 404 means not found, 500 server error, 201 created (not for DELETE).

3. Final Answer:

   200 -> Option C

4. Quick Check:

   DELETE success = 200 OK [OK]

Hint: Successful DELETE usually returns 200 or 204 status code [OK]

Common Mistakes:

• Confusing 201 (created) with success for DELETE
• Assuming 404 means success
• Ignoring status code meanings

4. Consider this JavaScript fetch code to delete a post:

fetch('https://api.example.com/posts/10', {
  method: 'DELETE',
  body: JSON.stringify({ id: 10 })
})
.then(res => res.status)
.then(console.log)

What is the main issue with this code?

medium

A. The URL is incorrect

B. DELETE requests should not have a body

C. The method should be GET

D. Missing headers for JSON content

Solution

1. Step 1: Understand DELETE request body rules

   DELETE usually does not require a request body; many servers ignore or reject it.

2. Step 2: Identify the problem in code

   The code sends a JSON body with DELETE, which is often unnecessary and may cause errors.

3. Final Answer:

   DELETE requests should not have a body -> Option B

4. Quick Check:

   DELETE usually no body [OK]

Hint: Avoid sending body with DELETE requests [OK]

Common Mistakes:

• Adding unnecessary body to DELETE
• Confusing method with GET or POST
• Forgetting to check server docs for DELETE body support

5. You want to delete multiple resources in one request using REST API. Which approach is best practice?

hard

A. Send multiple DELETE requests, one per resource URL

B. Send a single DELETE request with a JSON array body listing IDs

C. Use POST method with action=delete and list of IDs in body

D. Use GET method with query parameters to delete resources

Solution

1. Step 1: Understand REST principles for DELETE

   DELETE targets a single resource URL. Bulk delete is not standardized and often unsupported.

2. Step 2: Evaluate options for bulk deletion

   Sending multiple DELETE requests (one per resource) is standard and reliable. Other methods misuse HTTP verbs or semantics.

3. Final Answer:

   Send multiple DELETE requests, one per resource URL -> Option A

4. Quick Check:

   One DELETE per resource URL [OK]

Hint: Delete resources one by one with separate DELETE requests [OK]

Common Mistakes:

• Trying to send bulk delete in one DELETE with body
• Using POST or GET to delete resources
• Assuming server supports bulk delete by default