Reading notes-JS advanced Programming-The sixth chapter object-oriented programming

There are two properties of ECMAScript	Data properties and Accessor properties
There are 4 characteristics of data attributes	Configurableenumerablewritablevalue the default value for the first three values is false for example object.defineproperty (person, "name", {writable:false, value: "Niko"}); Once the attribute is defined as not configurable, it cannot be changed back to configurable.
Properties of the Read attribute	var descriptor = object.getownpropertydescriptor (book, "_year") descriptor.valuedescriptor.configurable
Creating an object using the constructor pattern	function Person (name,age,job) {this.name = name;  This.age = age; This.sayname = function () {alert (this.name)}}
Creating objects in prototype mode	function person () {}person.prototype.name = "Jeff"; Person.prototype.age = 28 The advantage is that all object instances can share the properties and methods it contains, Person.prototype point to the prototype object and Person.prototpe.constuctor to the person
Judging type	Person.prototype.isPrototypeOf (Person1)//True object.getprototypeof (person1) = = Person.prototype); True
Determine if a property is in the prototype, not in the instance	function Hasprototypeproperty (object, name) {return!object.hasownproperty (name) && (name is Object);
Gets all enumerable instance properties on an object	Object.keys () method
If you want to get all the instance properties, whether it's enumerable or not, you can use the method	Object.getownpropertynames () DVar keys = Object.getownpropertynames (Person.prototype);//"Constructor name age job Sayname
You cannot determine the type of an object by using constructor	var friend = new person () friend instanceof Object//truefriend instanceof person//truefriend.constructor = = person//FAL Sefriend.constructor = = Object//True
What links are passed between instances and prototypes	It's just a pointer, not a copy.
Add a method to the prototype of the native object	String.prototype.startWith = function (text) {return This.indexof (text) = = 0}var msg = "Hello World" msg.startwith ("Hell O ");
	constructor mode is used to define instance properties, while prototype mode is used to define methods and shared properties function person (name, age, Job) {    this.name = name;  &nbs P This.age = Age;    this.job = job;} Person Protytype = {    constructor:person,    sayname:function () {         a Lert (this.name);   }}
Dynamic Prototyping Mode	function person (name, age, Job) {this.name = name this.age = age;     This.job = job;     if (typeof this.sayname! = "function") {Person.prototype.sayName = function () {}; }}
Parasitic constructor mode	Waiting to be mended
Secure constructor Mode	Waiting to be mended
Inherited	Waiting to be mended

Reading notes-JS advanced Programming-The sixth chapter object-oriented programming