router.METHOD()

router.METHOD(path, [callback, ...] callback)

The router.METHOD() methods provide the routing functionality in Express, where METHOD is one of the HTTP methods, such as GET, PUT, POST, and so on, in lowercase. Thus, the actual methods are router.get(), router.post(), router.put(), and so on.

You can provide multiple callbacks, and all are treated equally, and behave just like middleware, except that these callbacks may invoke next('route') to bypass the remaining route callback(s). You can use this mechanism to perform pre-conditions on a route then pass control to subsequent routes when there is no reason to proceed with the route matched.

The following snippet illustrates the most simple route definition possible. Express translates the path strings to regular expressions, used internally to match incoming requests. Query strings are not considered when performing these matches, for example “GET /” would match the following route, as would “GET /?name=tobi”.

router.get('/', function(req, res){
  res.send('hello world');
});

You can also use regular expressions—useful if you have very specific constraints, for example the following would match “GET /commits/71dbb9c” as well as “GET /commits/71dbb9c..4c084f9”.

router.get(/^\/commits\/(\w+)(?:\.\.(\w+))?$/, function(req, res){
  var from = req.params[0];
  var to = req.params[1] || 'HEAD';
  res.send('commit range ' + from + '..' + to);
});