How to get javascript callback to work -

i have started learn javascript recently, , since i'm coming windows development world, i'm having hard time accepting js techniques..

i'm trying load several pictures @ same time in page using filereader. know need use asynchronous callbacks, seems can't work.

here's code:

function loadfile(file, callback) {     var reader = new filereader();     reader.onload = function(file) {         var output = document.createelement('input');         output.type = 'image';         output.classlist.add('image-responsive');         output.src = reader.result;          var x = document.getelementbyid('origname');         x.appendchild(output);     }     loadfile(file, callback);  }  (var = 0; < evt.target.files.length; i++) {     var file = evt.target.files[i];     loadfile(file); } 

can please me fix this?

i think have misunderstood how callbacks work. want more this:

function loadfile(file, callback) {     var reader = new filereader();     reader.onload = function(file) {         var output = document.createelement('input');         output.type = 'image';         output.classlist.add('image-responsive');         output.src = reader.result;          var x = document.getelementbyid('origname');         x.appendchild(output);         return callback(output);     }  }  evt.target.files.foreach(function (file) {     loadfile(file, function (output) {         console.log(output);     });  }) 

this console.log output once each file loaded. should note though files may loaded in different order order in array.