Why "_=1389258551926" sent as query string parameters on ajax request?
ajax, javascript, jquery
Solution
This parameter is a timestamp. You can see it's strangely alike what you'd get in the console with
Date.now()
This is done to ensure the URL changes and avoid receiving a cached version of the page.
It's described in the documentation :
cache (default: true, false for dataType 'script' and 'jsonp')
Type: Boolean If set to false, it will force requested pages not to be cached by the browser. Note: Setting cache to false will only work correctly with HEAD and GET requests. It works by appending "_={timestamp}" to the GET parameters. The parameter is not needed for other types of requests, except in IE8 when a POST is made to a URL that has already been requested by a GET.
Problem
I am using JQuery Ajax to send request to my action class with `data: {campaignId: campaignId}` but `_=1389258551926` also sent as data. My ajax request function is: ``` $('#submit').click(function() { var campaignId = $('#campaign').val(); alert("Ajax request ; Camp : " + campaignId); $.ajax({ type: "get", url: "getCampData", data: {campaignId: campaignId}, dataType: "json" }).done(function(data) { alert("Camp List : " + data.campList); }); ``` Query String parameters: ``` campaignId=Test&_=1389258551927 ``` Why this extra parameter sent as data?