Javascript function return always undefined -

new js i'm expecting bug easy fix.

so i've go function in users.js file :

exports.authenticate = function(user){ user.findone({     'username':user.username,     'password':user.password, },'username', function (err, dbuser) {         if (err) return handleerror(err);         console.log(boolean(dbuser));         return boolean(dbuser);      }); } 

so return value of dbuser boolean : true if exists, else false. quite simple no ? there come trap..

var userclass = require('./users.js'); var myuser = userclass.create('xxazeddax','azezaeazeazeaz','mazeazeazezaeaze'); var authent  = userclass.authenticate(myuser); console.log(authent); 

here i'm expecting boolean value because it's thing authenticate() can return.. not , got undefined. please, did got wrong ?

your function(user) a.k.a authenticate not return other function function (err, dbuser) callback function means executed when request completed, however, since callback funtion means function(err, dbuser) not meant executed sequentially.

i recommend article understand happening

http://www.impressivewebs.com/callback-functions-javascript/

i quick way see going on change code in way:

function(user){      user.findone({'username':user.username,'password':user.password},'username',       function (err, dbuser) {         if (err) return handleerror(err);         console.log(boolean(dbuser));         return boolean(dbuser);     });   return true; //<-- authenticate return true }