Q5: What is the role of the `next()` function in Express middleware?
The next() callback instructs Express to invoke the next middleware function registered in the execution pipeline.
Calling Modes
next(): Pass control to the immediate next middleware.next('route'): Skip remaining middleware in current router block and jump to next route matching current path.next(error): Skip all remaining processing middleware and jump straight to registered Error-Handling Middleware.
Key Takeaways
- Passing any truthy argument into
next(err)triggers Express error-handling mode. - Always return after calling
next()if code execution continues below it.