asynccallback

I am writing code for getting data. First I call **getsomedata** function to get data and inside getsomedata function I am calling another function getRandomdata to get data and returning it back to the previous function but it is returning undefined . But in getRandomdata data could be seen in console.log . Do I need to use callbacks ? router.get('/get-data', function (req, res, next) { var result = getsomedata(some_parameter); console.log(result); // receiving undefined res.send(result); }); function getsomedata(some_parameter_recieved) { var getsomedata = getRandomdata(random_params);

I want to get my result from an Async task. If I use task.execute.get, my UI will be frozen. I want my Async task will be stand alone class so I don't want to put my result processing code in onPostExecute. I've found some information about call back data from Async task here: http://blog.evoxmusic.fr/content/how-implement-callback-asynctask and here: android asynctask sending callbacks to ui but the problem is: 1-I don't know when to process the result? 2-why to use interface? 3-What's the differences of using an interface with simply putting the result in a public field in Async task from

I've been struggling with this for a while now. I'm new to Javascript, and have been under the impression that the code I've been writing has been running asynchronously. Here is a generic example: I run some code in function a. Function A then calls Function B, who needs to return a variable to A so A can use it in its later operations. It seems though that when A calls B, it still continues to run its own code, not waiting blocked for its return value, and B isn't fast enough such that A ends up reaching the point where it would have needed to use the return value and I get an undefined

I need a Label that is transmitted to the AsyncSendRegistrationMethod in CallbackMethodSendRegistration. private delegate ResponceFromServer AsyncSendRegistrationDelegate(RegistrationToUser registrationToUser, Label label); private ResponceFromServer AsyncSendRegistrationMethod(RegistrationToUser registrationToUser, Label label) { SetText(label, registrationToUser.Name + " registration..."); return Requests.DataBase.Authorization.Registration( registrationToUser.Name, registrationToUser.IdRoleUser, registrationToUser.IdGroup); } private void CallbackMethodSendRegistration(IAsyncResult ar) {

I'm new to JavaScript and to node.js. I want to loop through a directory and add all file stat (not other directories) to an array. As you see below there is a problem with my code since the callback will probably get called after the for loop has finished so using the "i"-variable in the callback method will not work. But how should the code look so that the below snippet works? Does it have something to do with closures? Thanks for help! fs.readdir(SYNCDIR, function(err1, files) { var filesOnly = []; if(!err1) { for(var i = 0; i < files.length; i++) { var imgFilePath = SYNCDIR + '/' + files

I am trying to grasp on Javascript Asynchronous functions and callbacks. I got stuck on the concept of callback functions, where I am reading on some places: they are use to have sequential execution of code (mostly in context of jquery e.g animate)and some places specially in the context of Nodejs; they are use to have a parallel execution Asynchronous and avoid blocking of code. So can some expert in this topic please shed light on this and clear this fuzz in my mind (examples??). so I could make my mind for the usage of callback function or that is solely depends on the place of where you