node.js - Can I pass a parameter into a findbyid() function in Mongoose -

i have variable user want push users array in express update request.

router.put( '/projectuser/:id', function( req, res ) {     var projectid = req.params.id;     var users = req.body.project.users;     var user = req.body.user;       return projectprofile.findbyid( projectid, function( err, project, user ) {         console.log(user);         console.log(project);          project.users.push(user);           return project.save( function( err ) {             if( !err ) {                 console.log( 'project users updated' );                 return res.send( project );             } else {                 console.log( err );                 return res.send('error');             }         });     }); }); 

in example variable user pushed users array undefined out of scope.

is there anyway pass variable user parameter in findbyid function?

couldn't understand question, think trying add userid value (req.body.user) users (array) property of projectprofile model. right?

if that's case believe code should (i'm leaving aside validations, error checking, duplicate checking, etc. use reference)

router.put('/projectuser/:id', function(req, res) {   return projectprofile.findbyid(req.params.id, function(err1, project) {     project.users.push(req.body.user);     return project.save(function(err2) {       return res.send('ok');     });   }); }); 

please check model#findbyid docs, save() callback takes 2 arguments, not 3.