MEAN Express.js Middleware and Routing 3

Question 1

What is the purpose of the `helmet` middleware in an Express application?

Accepted Answer

Sets security-related HTTP response headers to protect against common attacks

Answer

Helmet sets various HTTP headers like Content-Security-Policy, X-Frame-Options, and X-XSS-Protection to improve Express app security.

Question 2

Which Express method is used to redirect a client to a different URL?

Accepted Answer

res.redirect()

Answer

res.redirect() sends a response with a 3xx status code (default 302) and a Location header pointing to the target URL.

Question 3

What is rate limiting in Express and which package is commonly used?

Accepted Answer

Limiting requests per time window using express-rate-limit to prevent abuse

Answer

Rate limiting restricts the number of requests a client can make in a time window; express-rate-limit is the most popular package for this in Express.

Question 4

In Express.js, what is the difference between `app.get()` and `app.use()` for the same path?

Accepted Answer

app.get() only matches exact GET requests; app.use() matches all methods and also sub-paths

Answer

app.get() strictly matches GET requests at the exact path, while app.use() matches any HTTP method and any path that starts with the given prefix.

Question 5

How do you handle 404 errors for unmatched routes in Express.js?

Accepted Answer

Add a middleware with app.use() after all routes that sends a 404 response

Answer

A catch-all middleware added after all route definitions with app.use() will handle any request that didn't match a route and return a 404 response.

MEAN - Stack Development Practice Test

MEAN - Stack Development Practice Test

MEAN Express.js Middleware and Routing 3