Read this tutorial and learn about how the Access-Control-Allow-Origin response header works. Also, read about CORS, the origin, and non-simple requests.
You can either loop through the arrays or convert them to string and then compare. This tutorial provides several fast methods of comparing two arrays.
Here, we will share with you how to create a jQuery Ajax post request with PHP. Just check out the examples and choose the one that suits your needs best.
JSON is a data-interchange format, which can be generated and parsed by PHP or other programming languages. See how to create and parse JSON data by PHP.
This short tutorial will represent to you the most effective way of returning JSON from a PHP script.