404 Not Found in Rest API - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the HTTP status code returned when a requested resource is not found?

When a client requests a resource from a REST API that does not exist, what HTTP status code should the server return?

A 404 Not Found

B 200 OK

C 500 Internal Server Error

D 301 Moved Permanently

💡 Hint

Think about the code that means the resource is missing.

The 404 Not Found status code means the server can't find the requested resource. It tells the client that the URL is valid but the resource is missing.

❓ Predict Output

intermediate

What is the typical JSON response body for a 404 Not Found error?

A REST API returns a 404 Not Found status. Which JSON response body best describes this error?

A {"message": "Internal server error"}

B {"success": true}

C {"error": "Resource not found"}

D {"redirect": "/home"}

💡 Hint

The response should explain the resource is missing.

The JSON body usually contains an error message explaining the resource was not found. Option C clearly states this.

🔧 Debug

advanced

Why does this REST API endpoint return 404 Not Found unexpectedly?

Given this code snippet for a REST API endpoint, why might it return 404 Not Found even when the resource exists? ```python @app.route('/items/') def get_item(item_id): item = database.get(item_id) if not item: return {'error': 'Item not found'}, 404 return item ``` Options:

A The database.get(item_id) returns None because item_id is a string, not an int

B The route expects an integer but the client sends a string, so the route does not match

C The function returns 404 even if the item exists due to a missing return statement

D The server is down, causing all requests to return 404

💡 Hint

Check the route parameter type and what the client sends.

The route expects an integer parameter. If the client sends a string that cannot convert to int, the route won't match and Flask returns 404 automatically.

🧠 Conceptual

advanced

What is the difference between 404 Not Found and 410 Gone in REST APIs?

Which statement correctly explains the difference between HTTP status codes 404 Not Found and 410 Gone?

A 404 means the resource is temporarily missing; 410 means it is permanently removed

B 404 means the resource is permanently removed; 410 means it is temporarily missing

C 404 and 410 mean the same and can be used interchangeably

D 404 means server error; 410 means client error

💡 Hint

Think about temporary vs permanent absence.

404 Not Found means the resource is not found but might come back later. 410 Gone means the resource was intentionally removed and will not return.

📝 Syntax

expert

Which code snippet correctly returns a 404 Not Found response with a custom message in a Node.js Express app?

Choose the code that sends a 404 status with JSON message 'Page not found' in Express.js:

A res.status(404).send({message: 'Page not found'})

B res.send(404, {message: 'Page not found'})

C res.sendStatus(404).json({message: 'Page not found'})

D res.status(404).json({message: 'Page not found'})

💡 Hint

Check the correct method to send JSON with status.

In Express.js, res.status(404).json(...) sets the status and sends JSON. Option D is correct. Option D sends JSON but not guaranteed. Option D is deprecated syntax. Option D sends status and ends response, so chaining json() fails.