JavaScript Advanced (5)---writing class

Scripting of JavaScript classes

• Defining variables and methods internally

2. The this declaration is used to define common public properties and public methods
4. In the internal var declaration, or simply do not write Var (implicitly declared) is the dead Yo property with private method
5. An instance of a class can only access public properties and public methods

    　　 functionPet (_name,_age,_price) { This. name=_name; varAge=_age;//Private Properties  　　  varPrice=_price;//Private Properties   　　  This. Setage =function(IntAge) { age=IntAge; }/*to define a private property an external public access method for age*/   　　   This. Getage =function() {returnAge ; }   }

• Use prototype to define methods and properties on the prototype chain

1. The properties and methods defined using prototype are all common
2. The notation ① gives a common construction method within the class or ② directly defines the class as empty, and then writes the prototype of the class directly into the form of a JS object

　　Writing one:

/*define a pet class using the notation ①*/functionPet (_name, _age, _price, _color) { This. Init (_name, _age, _price, _color); Pet.prototype.name; Pet.prototype.age; Pet.prototype.price; Pet.prototype.color; Pet.prototype.init=function(_name, _age, _price, _color) {if(_name! = undefined && _age! = undefined && _price! = undefined && _color! =undefined) {         This. Name =_name;  This. Age =_age;  This. Price =_price;  This. color =_color; Document.writeln ("This.name=" + This. Name + ", this.age=" + This. Age + ", this.price=" + This. Price + ", this.color=" + This. color); }}

　　Two:

functionPerson2 () {}
/*constructs a class in the form of a JS object on the prototype of a class*/Person2.prototype={name:"",//Public Propertyage:0, weight:0, height:0,/*Public Method*/Init:function(_name, _age, _weight, _height) { This. Name =_name;  This. Age =_age;  This. Weight =_weight;  This. Height =_height; Document.writeln ("This.name=" + This. Name + ", this.age=" + This. Age + ", this.weight=" + This. Weight + ", this.height=" + This. Height); },    /*Public Method*/Show:function() {Document.writeln ("Show Method"); }};

　　

Using the above inductive characteristics, we can summarize a set of efficient and feasible writing method

• Use constructors to define the public property ,private property
• Use the prototype chain prototype to define the methods of the class (public method), and then use these methods to access public and private properties

/*define a person class*/functionPerson (_name, _age, _price) { This. Name =_name; varAge =_age; //private properties that can only be used inside a class    varPrice =_price; //private properties that can only be used inside a class    functionPrivatefn () {Console.log ("I am a private attribute of the Pet class age, can only be used inside the pet class, after initialization age=" +Age ); Console.log ("I am a private function of pet class Privatefn, can only be used inside the pet class"); }    varPRIVATEFN2 =function() {Console.log ("I am the Pet class's private property price, can only be used inside the pet class, after initialization price=" +Price ); Console.log ("I am a private function of pet class PRIVATEFN2, can only be used inside the pet class");    } privatefn (); //calling private methods inside a pet classprivateFn2 (); //calling private methods inside a pet class}pet.prototype={setName:function(_name) { This. Name =_name; }, GetName:function ()    {        return  This. Name; }, Show:function() {Console.log ("Public Method Show");　}}; 

Reference: http://www.cnblogs.com/xdp-gacl/p/3700840.html

　　

JavaScript Advanced (5)---writing class