router---dynamic route matching

1. Dynamic routing usage scenarios or path parameter usage scenarios

We need to map the routes of the given matching pattern to the same component, we need to use the path parameterOr the same component, the path parameters are the same, the display is different

Second, matching mode, matching path, parameter acquisition

Match Pattern	match path	Parameter acquisition
/users/:username	/users/jim	$router.params.username
/users/:username/:userid	/users/jim/123	$router.params.username $router.params.userid

Three, how to respond to this routing change

1, monitor $router.params2. beforeRouteUpdate(to, from, next){to.params.id}