JS17---Create objects: constructor and prototype combination modes, dynamic prototype patterns, secure constructor functions

<!DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01//en" "HTTP://WWW.W3.ORG/TR/HTML4/STRICT.DTD"><HTML>    <Head>        <Metahttp-equiv= "Content-type"content= "text/html; charset=utf-8" />        <title>Untitled Document</title>        <Scripttype=text/javascriptCharSet=utf-8>        //Customizing the prototype object alters the constructor of the prototype object.         //Concept of Prototypes: All properties and methods in the prototype object are shared by objects instantiated by all constructors        functionPerson () {} Person.prototype={constructor:person, Name:'Z3', Age: -, Job:'Programmer', friends: ['John Doe','Harry'], Sayname:function() {alert ('My name!')}        }; varP1= NewPerson (); varP2= NewPerson (); P1.friends.push ('Zhao Liu');//the. Push method of the arrayalert (p1.friends);//Change thealert (p2.friends); //we generally use a combination of a constructor and a prototype model, which is the most widely used in real-world development.         //use a combination of prototypes and constructors (a common way of defining a class development), not just a constructor or a prototype.         functionPerson (name, age, friends, job) { This. Name=name;  This. Age=Age ;  This. Friends=friends;  This. Job=job; } Person.prototype={Constructor:person, sayname:function() {alert ( This. Name);//Who calls Sayname,this is who            }        }; varP1= NewPerson ('Z3' ,  - , ['Harry','Zhao Liu'] , 'Technical Director'); varP2= NewPerson ('John Doe',  - , ['Harry','Zhao Liu' ,'Zhao 7'] ,'boss');        alert (p1.friends);        P1.sayname ();        alert (p2.friends);                                                P2.sayname (); //Dynamic Prototyping mode: (Let your code wrap together). Dynamic prototype mode: It is to encapsulate the information into functions, which embodies the concept of encapsulation.         functionPerson (name, age, friends, job) { This. Name=name;  This. Age=Age ;  This. Friends=friends;  This. Job=job; //Dynamic Prototyping methods:            if( typeof  This. Sayname!= 'function'){//The first time new person will add this method to the prototype, the second time the new person object is not created. typeof is lowercase function,constructor is uppercase functionPerson.prototype.sayName= function() {alert ( This. Name); }            }        }            /*var o = {name:2, Age: ""} alert (O.sayname);//undefined A Lert (typeof o.sayname);//undefined*/                                        //Secure constructor: Durable object (Safe object) in a very secure environment        //1 No public properties, 2 cannot use this object        functionPerson (name, age, job) {//create an object to return, Factory mode,                varobj= NewObject (); //You can define a private variable and function Private,js inside is a var local variable, external access, internal functions, similar to Java inside through the private declaration of some variable methods.                 varname=name; //var sex = ' male ';                //var saysex = function () {};                //Add a methodObj.sayname= function() {alert (name); }                returnobj; }        varP1= NewPerson ('Zhang San');        P1.sayname (); </Script>    </Head>    <Body>    </Body></HTML>

JS17---Create objects: constructor and prototype combination modes, dynamic prototype patterns, secure constructor functions