Form data as json object

serialiser.js

const serialize = function($form){
  if(!$form) return {};
  var obj = {};
  var elements = $form.querySelectorAll( "input, select, textarea" );
  for( var i = 0; i < elements.length; ++i ) {
    var element = elements[i];
    var name = element.name;
    var value = element.value;
    if(name){
      obj[name] = value;
    }
  }
  return obj;
};
// use as:
const data = serialize(document.querySelector('form'));