An object: a package of data, a plurality of data storage container (unified management of multiple data)
1 classification
1) built-in objects: Object defined by the standard ES, can be used in the implementation of any ES
例如：Math String Number Function Object
2) Host: Object provided by the operating environment JS
For example: DOM BOM
3) custom objects: user-defined
2, consists of:
- Properties: constituted by the attribute name (character string) and an attribute value (of any type)
- Method: A special attribute (function value)
3, the internal data access objects
- Object attribute name: attribute name uncertain (variable); can not be used when the attribute names with special characters
- Object [property name]: can be used under any circumstances
Second, the way to create objects
1, new operator: create an empty object, and then dynamically add attributes. When the internal properties of the object initially uncertain
Cons: Too many statements
2, object literal: When you create an object suitable for internal property is determined.
Disadvantages: When you create multiple objects, a lot of code duplication
3, using the factory method: dynamic functions create objects through the factory, and the object is returned. For creating multiple objects
Cons: There is no specific type of the object, you can not determine who is an instance of Object
4, constructed function
And the difference between the way the factory function: to create an object is not displayed; there is no return statement; constructor name the general needs of capital, other general lowercase; know who is an example
(Examples of which can be seen by both Object instanceof, which is an instance of Person)
The creation of objects:
1) Create an object immediately
2) The scope of the constructor is assigned to the new object (so this point a new object)
3) code is performed row by row constructor
4) The new object is returned
Cons: If you write a function in the constructor method, then each time you create an object will instantiate a method (method is a function, the function is the object), the methods of each object
Different. The method functions written on the outside will pollute the global namespace, and not enough privacy. This presented a prototype way to create an object
5, the constructor prototype +
向对象的原型中添加一些公有的属性，这样每次创建对象时就不会都重复创建。