return results from a function javascript nodejs

Question

Could anyone help me with this code  I need to return a value form a routeToRoom function   var sys   require  sys     function routeToRoom userId  passw        var roomId   0      var nStore   require  nstore lib nstore   extend require  nstore lib nstore query           var users   nStore new  data users db   function              users find               user  userId              pass  passw             function err  results                if  err                    roomId   -1                else                   roomId   results creationix room                                                  return roomId    sys puts routeToRoom  alex    123       But I get always  0  I guess return roomId  is executed before roomId results creationix room  Could someone help me with this code

User · Answer

You are trying to execute an asynchronous function in a synchronous way  which is unfortunately not possible in Javascript   As you guessed correctly  the roomId results     is executed when the loading from the DB completes  which is done asynchronously  so AFTER the resto of your code is completed   Look at this article  it talks about  insert and not  find  but the idea is the same   http   metaduck com 01-asynchronous-iteration-patterns html

User · Answer

function routeToRoom userId  passw  cb        var roomId   0      var nStore   require  nstore lib nstore   extend require  nstore lib nstore query           var users   nStore new  data users db   function             users find               user  userId              pass  passw            function err  results                if  err                    roomId   -1                else                   roomId   results creationix room                            cb roomId                         routeToRoom  alex    123   function id        console log id             You need to use callbacks  That s how asynchronous IO works  Btw sys puts is deprecated

[javascript] return results from a function (javascript, nodejs)

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