Can't get value of input type=“file”?

Question

I have a <input type="file" id="uploadPicture" value="123">

When I'm using: alert($("#uploadPicture").val());

It alerts an empty dialog.

Answer 1

don't give this in file input value="123".

  $(document).ready(function(){  

      var img = $('#uploadPicture').val();

  });