Three roles of JS Learning summary----function

Note: Function.prototype is the value of the function data type, but the related operation is exactly the same as before->empty/anonymous

The function itself will have its own properties:

Length: The number of formal parameters

Name: Name of "Fn" function

Prototype of the prototype class, the method defined on the prototype is the public method of the current FN class instance.

__proto__ functions as a normal object, pointing to the prototype of the function class.

function is the most complex and important knowledge in the whole JS:

1, a function has a multi-faceted nature:

　　　　"Normal function": itself is a normal function, the execution of the time will form a private scope (closure), parameter assignment, pre-interpretation, code execution, after the completion of the stack memory destroyed/not destroyed

　　　　"Class": It has its own instance, and there is a prototype called the prototype property, and his instance can point to his own prototype

　　　　"Normal Object": Like obj in var obj = {}, it is an ordinary object that can have its own private property as an object, or it can be found by __proto__ Function.prototype

There is no definite relationship between the three of them.

functionFn () {varnum = 500;  This. x = 100; } Fn.prototype.getX=function() {Console.log ( This. X)} FN.AAA= 1000; varf =NewFn; F.num//undefinedF.aaa//undefined        varres =Fn (); Res//undefinedFn.aaa// +

JS Learning summarizes the three roles of----functions