Objects

    /*
    You can put together different variables, arrays and object into 
    other objects and arrays.
    This is called JSON (JavaScript Object Notation)
    http://json.org
    JSON is valid JavaScript code
    */
    var o = {"a":"Hello World","b":5.5,"c":true,"x":[1,2,3]};//Object  
    var ao = [{"a":7,"b":100},{"a":5,"b":42.23}];//Array Object  
    var arr = ["a","b","c"]; var n = a.length;

    /*
    Everything is an object and has own properties and functions like
    the array.length or string.split("")
    
    You can also create your own objects that have functions
    */
    
    var an_obj = {"key":"value",
                "split_and_return_value":function (){
                var res = this.key.split("");
                return res;
                }
    };
    alert(an_obj.split_and_return_value());

####Looping Objects
The for(var key in object) can be used to loop objects. Here the key is not but can be an index. Important is - it also can be the name of an property. Don't use these loops an Arrays! Have a look at this stackoverflow

    var obj = {
        "a":"Hello World",
        "b":5.5,
        "c":true,
        "x":[1,2,3]
    };//Object  

    for ( var key in obj ){ 
         if (obj.hasOwnProperty(key)){
        alert( key );
      }
    }  
    alert(obj["a"]);

see also Object Watch for a ExtendScript (and Mozilla JS) special move.