Response envelope patterns in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a basic response envelope with a status field.

Rest API

response = {"status": "[1]"}

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

Afailed

Berror

Cpending

Dsuccess

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'error' instead of 'success' for a successful response.

The status field in a response envelope usually indicates if the request was successful. Here, "success" is the correct value.

2fill in blank

medium

Complete the code to add a data field to the response envelope.

Rest API

response = {"status": "success", "[1]": {"id": 1, "name": "Item"}}

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

Aerror

Bdata

Cmessage

Dresult

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'error' or 'message' instead of 'data' for the content field.

The data field holds the actual content or payload of the response. "data" is the standard key used.

3fill in blank

hard

Fix the error in the response envelope by completing the missing key for error details.

Rest API

response = {"status": "error", "[1]": "Invalid request parameters."}

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

Amessage

Berror

Cresult

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'data' or 'result' keys for error messages.

The error message should be under a key like "message" to clearly describe the problem.

4fill in blank

hard

Fill both blanks to create a response envelope with status and nested data count.

Rest API

response = {"[1]": "success", "data": {"count": [2]

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

Astatus

Btotal

Citems

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'total' or 'items' as the status key.

Putting a string instead of a number for count.

The top-level key for status is "status" and the count value is a number like 5.

5fill in blank

hard

Fill all three blanks to create a full response envelope with status, data list, and message.

Rest API

response = {"[1]": "success", "[2]": [{"id": 1}, {"id": 2}], "[3]": "Request completed."}

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

Astatus

Bdata

Cmessage

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up 'error' with 'message' or 'data'.

The keys are "status" for the response state, "data" for the list of items, and "message" for a descriptive text.

Practice

1. What is the main purpose of using a response envelope in REST APIs?

easy

A. To increase the size of the response for security

B. To wrap the actual data with status and messages for clarity

C. To hide the data from the client

D. To make the API slower intentionally

Solution

1. Step 1: Understand what a response envelope is

   A response envelope is a structure that wraps the main data with extra information like status and messages.

2. Step 2: Identify the purpose of wrapping data

   This wrapping helps clients quickly understand if the request succeeded or failed and provides useful messages.

3. Final Answer:

   To wrap the actual data with status and messages for clarity -> Option B

4. Quick Check:

   Response envelope = Wrap data with status and messages [OK]

Hint: Response envelopes add status and messages around data [OK]

Common Mistakes:

• Thinking response envelopes hide data
• Believing they slow down the API on purpose
• Confusing response envelopes with security features

2. Which of the following is the correct JSON structure for a simple response envelope?

easy

A. {"status": "success", "data": {"id": 1, "name": "Alice"}}

B. {"data": {"id": 1, "name": "Alice"}, "error": null}

C. {"result": {"id": 1, "name": "Alice"}}

D. {"message": "success", "payload": {"id": 1, "name": "Alice"}}

Solution

1. Step 1: Identify the typical keys in a response envelope

   Common keys include "status" for success/failure and "data" for the actual content.

2. Step 2: Check each option for correct keys and structure

   {"status": "success", "data": {"id": 1, "name": "Alice"}} uses "status" and "data" correctly. Others use different or missing keys.

3. Final Answer:

   {"status": "success", "data": {"id": 1, "name": "Alice"}} -> Option A

4. Quick Check:

   Correct keys = status + data [OK]

Hint: Look for 'status' and 'data' keys in JSON [OK]

Common Mistakes:

• Using 'result' or 'payload' instead of 'data'
• Missing the 'status' key
• Confusing 'error' with 'status'

3. Given this response envelope JSON:

{"status": "error", "message": "Not found", "data": null}

What should the client understand from this response?

medium

A. The request succeeded and data is available

B. The server returned invalid JSON

C. The request succeeded but data is empty

D. The request failed and no data is returned

Solution

1. Step 1: Analyze the 'status' field

   The status is "error", indicating the request did not succeed.

2. Step 2: Check the 'message' and 'data' fields

   The message says "Not found" and data is null, meaning no data was returned due to an error.

3. Final Answer:

   The request failed and no data is returned -> Option D

4. Quick Check:

   Status 'error' + null data = failure [OK]

Hint: Check 'status' first to know success or failure [OK]

Common Mistakes:

• Assuming 'error' means success
• Ignoring the 'message' field
• Thinking null data means empty success

4. You have this response envelope:

{"status": "success", "data": {"id": 5}}

What is wrong with this response?

medium

A. Missing closing brace for JSON object

B. Missing 'message' field in the envelope

C. Data should be an array, not an object

D. Status should be 'ok' instead of 'success'

Solution

1. Step 1: Check JSON syntax

   The JSON string ends after "id": 5 without closing the outer object with a brace.

2. Step 2: Validate required fields

   While 'message' is optional and 'data' can be an object, the missing brace is a syntax error.

3. Final Answer:

   Missing closing brace for JSON object -> Option A

4. Quick Check:

   JSON must have matching braces [OK]

Hint: Always check JSON braces for completeness [OK]

Common Mistakes:

• Assuming 'message' is mandatory
• Thinking 'data' must be an array
• Confusing status values

5. You want to design a response envelope that includes:
- A status code (number)
- A success boolean
- A message string
- The actual data

Which JSON structure best fits this requirement?

hard

A. {"result": {"code": 200, "message": "OK"}, "payload": {"user": "Bob"}}

B. {"status": "success", "data": {"user": "Bob"}}

C. {"code": 200, "success": true, "message": "OK", "data": {"user": "Bob"}}

D. {"success": "true", "code": "200", "msg": "OK", "data": {"user": "Bob"}}

Solution

1. Step 1: Match required fields with options

   Required fields are numeric status code, boolean success, message string, and data object.

2. Step 2: Check each option for correct types and keys

   {"code": 200, "success": true, "message": "OK", "data": {"user": "Bob"}} uses 'code' as number, 'success' as boolean, 'message' as string, and 'data' correctly. Others miss types or keys.

3. Final Answer:

   {"code": 200, "success": true, "message": "OK", "data": {"user": "Bob"}} -> Option C

4. Quick Check:

   Correct keys and types = {"code": 200, "success": true, "message": "OK", "data": {"user": "Bob"}} [OK]

Hint: Check data types match requirements exactly [OK]

Common Mistakes:

• Using strings instead of boolean or number
• Missing some required fields
• Using inconsistent key names