Old fish talking about javascript Object-Oriented Programming _ js object-oriented

This week's painstaking efforts have turned to the underlying code of several popular JS Script frameworks. Although the code is easy to understand, it has benefited a lot and lamented the greatness of people first ...... The exclamation is to ease the serious atmosphere and bring out the topic to be discussed today, "javascript object-oriented programming". Next, we will focus on several major object-oriented keywords: encapsulation, inheritance, and polymorphism, expand.
Encapsulation: In the mode in which objects are created in javascript, I personally think that the closure is actually an encapsulation. So first, let's briefly introduce the closure and take a look at the following example:

The Code is as follows: