only_use_latest_arriving_ajax_answer.js

// Say, you want only to use the latest arriving ajax request.
// For example in a search engine, where only the request of the
// most recently sent request is of interest. Responses that come
// after and have been sent before the one that has already arrived
// are ignored:

// remember the latest request date
//
var latestRequestDate = new Date();
function responseHandler() {
  // bind a timestamp to the current time
  var requestDate = new Date();
  
  // This function only does what it does if the
  // request is the most recently sent request and none other
  // has arrived earlier.
  return function(response) {
    if (requestDate < latestRequestDate) { return; }
    latestRequestDate = requestDate;

    // handle the response here
    // …
    //
  };
  
}

// Where you send the request
//
$.get(url, params, responseHandler(), 'json');