how to give properties to var javascript code example

Example 1: javascript object

var	person = {
	first_name : "Marty",
  	last_name : "Mcfly",
	born : 1968,
	died : 1933,
    lovers: ["Jennifer Parker","Baines McFly"]
};

Example 2: javascript add to object

var element = {}, cart = [];
element.id = id;
element.quantity = quantity;
cart.push(element);

// Array of Objects in form {element: {id: 10, quantity: 10} }
var element = {}, cart = [];
element.id = id;
element.quantity = quantity;
cart.push({element: element});