jquery--new返回值 

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type=text/javascript charset=utf-8>

function F(){
    this.name = 1;
    this.sc = 4;
    alert(2);
    return function(){
        this.age = 2;
        this.name = 3;
        alert(1);
    }
}
var f = new F();
alert(typeof f);//function
alert(f.name);//输出函数的名字
alert(f.age);//undefined
alert(f.sc);//undefined        

function G(){
    this.name = 1;
    this.sc = 4;
    return {
        name : 14,
        age : 15
    };
}
var g =new G();
alert(typeof g);//object
alert(g.name);//14
alert(g.age);//15
alert(g.sc);//undefined

function H(){
    this.name = 1;
    this.sc = 4;
}
var g =new H();
alert(typeof g);//object
alert(g.name);//1

function H(){
    this.name = 1;
    this.sc = 4;
    return this;
}
var g =new H();
alert(typeof g);//object
alert(g.name);//1        
alert(g.sc);//4      

function L(){
    this.name = 1;
    this.sc = 4;
    return new Array(1,2,3);
}
var l =new L();
alert(typeof l);//object
alert(l);//1,2,3
alert(l.name);//undefined
alert(l.sc);//undefined  

function E(){
    this.name = 1;
    this.sc = 4;
    return 'ssss';//return的是引用类型new函数就返回return的引用类型对象，基本类型就还是返回函数类的实例对象。
}
var e =new E();
alert(typeof e);//object
alert(e);//object
alert(e.charAt(1));//e.charAt is not a function
alert(e.name);//1
alert(e.sc);//4
</script>
</head>
<body>
</body>
</html>

 

function F(){
    this.n = 1;
    this.sc = 4;
    return function FF(){
        this.n = 11;
        this.sc = 44;
        return function FFF(){
            this.n = 111;
            this.sc = 442;                    

        }
    }
}
var f = new F();
alert(typeof f);
alert(f.name);//FF, new　F()，函数F值执行他的那层执行一遍
alert(f.n)//undefined   


function F(a){
    this.n = 1;
    this.sc = 4;
    return new init(a);   //new init()，如果init类没有return引用就返回init类的对象，否则返回init类中return的引用对象
}

function init(){
    this.n = 11;
    return {n:arguments[0]}
}

var d = F(3);
alert(d.n);//3      



function F(a){
    this.n = 1;
    this.sc = 4;
    return new init(a);
}

function init(){
    this.n = 11;
    return 44
}

var d = F(3);
alert(d.n);//11

 new F() 不一定返回F类的对象，有可能返回F()函数里面返回的对象。

 

function F(a){
    this.n = 1;
    this.sc = 4;
    return new G(a); //不一定返回G对象,返回{}
}

function G(){
    this.n = 11;
    return {n:arguments[0]}
}

var d =new F(3); //不一定返回F的对象，返回的是F函数里面的new G()这个G的对象
alert(d.n);//3

 

posted @ 2017-05-24 14:18  无天666  阅读(466)  评论(0)  编辑  收藏  举报