04.对象和原型

 1             function User(name,passwordHash){
 2                 this.name=name;
 3                 this.passwordHash=passwordHash;
 4                 this.toString=function(){
 5                     return "[User "+this.name+"]";
 6                 }
 7                 this.checkPassword=function(password){
 8                     return hash(password)===this.passwordHash;
 9                 }
10             }

1             function CSVReader(separators) {
2                 this.separators = separators || [","];
3                 this.regexp = new RegExp(this.separators.map(function(sep) {
4                     return "\" + sep[0];
5                 }).join("|"));
6             }

1             CSVReader.prototype.read=function(str){
2                 var lines=str.trim().split(/
/);
3                 return lines.map(function(line){
4                     return line.split(this.regexp);//wrong this
5                 });
6             };
7             
8             var reader=new CSVReader();
9             reader.read("a,b,c
d,e,f
");//[["a,b,c"],["d,e,f"]]

1             CSVReader.prototype.read=function(str){
2                 var lines=str.trim().split(/
/);
3                 return lines.map(function(line){
4                     return line.split(this.regexp);
5                 },this);//forward outer this-binding to callback
6             };
7             
8             var reader=new CSVReader();
9             reader.read("a,b,c
d,e,f
");//[["a,b,c"],["d,e,f"]]

 1             CSVReader.prototype.read=function(str){
 2                 var lines=str.trim().split(/
/);
 3                 var self=this;
 4                 return lines.map(function(line){
 5                     return line.split(self.regexp);
 6                 });
 7             };
 8             
 9             var reader=new CSVReader();
10             reader.read("a,b,c
d,e,f
");//[["a,b,c"],["d,e,f"]]

1             CSVReader.prototype.read=function(str){
2                 var lines=str.trim().split(/
/);
3                 return lines.map(function(line){
4                     return line.split(this.regexp);
5                 }.bind(this));//bind to outer this-binding
6             };
7             
8             var reader=new CSVReader();
9             reader.read("a,b,c
d,e,f
");//[["a,b,c"],["d,e,f"]]

 1             function Scene(context, width, height, images) {
 2                 this.context = context;
 3                 this.width = width;
 4                 this.height = height;
 5                 this.images = images;
 6                 this.actors = [];
 7             }
 8 
 9             Scene.prototype.register = function(actor) {
10                 this.actors.push(actor);
11             }
12 
13             Scene.prototype.unregister = function(actor) {
14                 var i = this.actors.indexOf(actor);
15                 if(i >= 0) {
16                     this.actors.splice(i, 1);
17                 }
18             };
19             Scene.prototype.draw = function() {
20                 this.context.clearRect(0, 0, this.width, this.height);
21                 for(var a = thisactors, i = 0, n = a.length; i < n; i++) {
22                     a[i].draw();
23                 }
24             }

            function Actor(scene,x,y){
                this.scene=scene;
                this.x=x;
                this.y=y;
                scene.register(this);
            }

            Actor.prototype.moveTo = function(x, y) {
                this.x = x;
                this.y = y;
                this.scene.draw();
            }

            Actor.prototype.exit=function(){
                this.scene.unregister(this);
                this.scene.draw();
            }

            Actor.prototype.draw=function(){
                var image=this.scene.images[this.type];
                this.scene.context.drawImage(imgae,this.x,this.y);
            }

            Actor.prototype.width = function() {
                return this.scene.images[this.type].width;
            }
            Actor.prototype.height = function() {
                return this.scene.images[this.type].height;
            }

            function Actor(scene,x,y){
                this.scene=scene;
                this.x=x;
                this.y=y;
                this.id=++Actor.nextID;
                scene.register(this);
            }
            Actor.nextID=0;

            function Alien(scene, x, y, direction, speed, strength) {
                Actor.call(this, scene, x, y);
                this.direction = direction;
                this.speed = speed;
                this.strength = strength;
                this.damage = 0;
                this.id = ++Alien.nextID; //conflicts with actor id!
            }
            Alien.nextID = 0;