difference between 2 objects/arrays

i have 2 objects, which are associated arrays from PHP in JSON. They have an structure like that´:

[object]
    ["green"]
         ['value1']=integer
         ['value1']=array...
    ["blue"]
         ['value1']=integer
         ['value1']=array...
    [...]

The 1st Version of this object is loaded from webserver periodically using JSON. By receiving this new JSON string from webserver, the current object moved to the variable "oldObj" while the new data stored into the variable "newObj". It could be possible, that the new object will have less elements than the old object, like this:

[newObj]
    ["green"]
         ['value1']=integer
         ['value1']=array...

As you can see: "blue" is missing.

Now i need this elements which are part of the old Object / that means: which are missing at the new object (at t开发者_高级运维his example: element "blue")

I tried the following, but without any success:

[...]
    var newObj=data;
    $.each (oldObj,function(i,n)
            {if (newObj.i.length<1) {alert('missing: '+i);}
            }
         );//end foreach

Error message: "newObj.i is undefined"

---

According to your description, I think newObj or oldObj can be wrote as:

var newObj = {
    "green": [
        integer,
        [array]
    ],
    "blue": [
        integer,
        [array]
    ]
};    

Is it right?

You could use :

for(p in Obj){
    if(Obj.hasOwnProperty(p)){
        // do something with p
    }
}  

to loop through the Obj's properties.