What function are arguments available to Express JS route handlers?

The arguments which are available to an Express JS route handler-function are-

• Req – the request object
• Res – the response object
• Next (optional) – a function which is used to pass control to one of the subsequent route handlers.

The third argument is optional and may be omitted, but in some cases, it is useful where there is a chain of handlers and control can be passed to one of the subsequent route handlers skipping the current one.