what does the this and self mean in the code???

lang jianfeng · December 25th, 2011, 02:26 AM

<code>
var Scroll = new function(){
this.delay = 2000; //延迟的时间
this.height = 20; //行的高度
this.step = 4; //步长
this.curHeight= 0;
this.stimer = null;
this.timer = null;
this.start = function(){ //开始翻页-调用move方法
this.move();
}
this.move = function(){
var self = this;
if(this.curHeight == this.height) //如果显示完一行
{
this.timer = setTimeout(function(){ //使用定时器-定时下一行的翻页时间
self.move();
}, this.delay);
this.curHeight = 0;
if(this.element.scrollTop >= this.element.scrollHeight - this.height){ //滚动信息已经完毕
this.element.scrollTop = 0;
}
return true;
}
this.element.scrollTop += this.step;
this.curHeight += this.step;
this.timer = setTimeout(function(){ //设置自动翻页定时器
self.move();
}, 30);
}
this.stop = function(){ //清除定时期，停止滚动翻页
clearTimeout(this.timer);
}
}
</code>

anybody can help me analysize the code? it's too difficult to me!

irProject · February 18th, 2012, 04:06 AM

1- first note

Code:

var x = new function(){
    this.y = 2000; 
}

the above statement creates an object (class) named: x
and y property is added to x. 'this' refers to the object (x)

Code:

x.y = 288;

// or

x["y"] = 288;

irProject · February 18th, 2012, 04:09 AM

Code:

var x = new function(){
    this.y = 2000;
    this.move = function(){
        alert('move function called');
    };
}

x.move(); // shows alert

you can add methods like above

irProject · February 18th, 2012, 04:10 AM

Code:

var x = new function(){
    this.y = 2000;
    this.move = function(){
        startMove();
        // ...
        endMove();
    };
    this.startMove = function(){
        alert('started ... ');
    };
    this.endMove = function(){
        alert('ended ... ');
    };
}

x.move(); // shows alerts

you can call other methods like above

lang jianfeng · February 18th, 2012, 09:23 AM

thank you very much!