How to compare observable array list with firebase query data


#1

let’s say I have an observable array

var post = [ 
            {first: "Anthony", last: "Johnson"}
            {first: "Mary", last: "Dale"}
];

and I have same data from firebase from a query.
how do I compare both data list to determine if it is existing on the oberservable array
before pushing it through to the oberservable array list?