JS---Prototype

function person () {}
undefined
typeof person
the "function" //person is a constructor
P=new person ();
The person {} //p is an instance of the person function construct and is a person{} object
p.__proto__The //__proto__ property can only be used on an object, representing the object's prototype object. This property is valid in Firefox,chrome
Person {}
Person.prototypethe//prototype property can be used only on functions, and any function has that property, which is also an object.
Person {}
P.__proto__===person.prototype
True //When an object is created through a constructor, the prototype property of the constructor is assigned as a prototype to all object instances (also set the __proto__ property of the instance), meaning that all instances of the prototype reference are prototype properties of the function
p.__proto__.__proto__
The prototype of the object {} //instance P is a object{} object
person.prototype.__proto__
Object {}
Person.prototype.constructor//person{} object's constructor
The function Person () {} //"Person.prototype" object and the person function implement mutual references through "constructor" and "prototype".

JS---Prototype