Here's my quick tutorial:
JSON is a means for expressing data for arrays, objects, and their contents. It has nothing to do with object behaviour (methods).
<?php
class Test {
public $hello = 'hello';
public $something = array('hello1', 'hello2');
public __construct() {
}
public void printHello() {
echo $this->hello;
}
}
?>
This class would in JSON would look like:
var obj = {
"hello": "hello",
"something": ["hello1", "hello2"]
};
As you can see, JSON is similar to maps in a lot of languages (key/value pairs). You can also see, that only data is represented. JSON is also shorthand for JavaScript builtins. For example, this previous object can be written in JavaScript like so.
var obj = new Object();
obj.hello = "hello";
obj.something = new Array("hello1", "hello2");
Hope this gives you a little idea of what JSON is about.