js getters and setters

batch.js

var o = {};

Object.observe(o, function(records) {
    console.log(records);
});

// the following three changes are batched, as they occur
// within the same frame of the loop
o.x = "foo";
o.y = "bar";
o.z = "baz";

// these two instances will be batched separately
// in their own frame
setTimeout(function() {
    o.a = "bah";
    o.b = "blergh";
}, 100);

old.js

var o = {
    "_x": "foo",
    get x() {
        return this._x;
    },
    set x(val) {
        this._x = val;
    }
};

console.log(o.x); // "foo"
o.x = "bar";
console.log(o.x); // "bar"