Q:

Is possible to use push method with objects ?

As you can see in the following code the method works with an object, why does it work,? is it because I am accessing the name which is an array ?
var person = {
    name : []
};

person["name"].push('Mark');

A:

Exactly, the object contains a property named 'name' which is an array object. You can reference this in 2 different ways. By name and by property.
person.name.push('Mark') 

would work as well as 
person['name'].push('Mark')

The great thing about javascript objects is that you can add any type of object to a javascript object's structure.
Your javascript object just happens to contain an array object which can be pushed to like a normal array.

