this.prototype={constructor:this};

function F(){};
F.prototype={constructor:'1111'};
var o=new F();//o.constructor===‘1111' true

//instanceof實現
function Myinstanceof(obj,type)
{
var proto=obj.__proto__;
while(proto)
{
if(proto ===type.prototype)break;
proto=proto.__proto__;
}
return proto!=null;
}


function View(){}
function TreeView(){}
TreeView.prototype=new View();//TreeView.prototype.__proto__=TreeView.prototype 自動完成
TreeView.prototype.constructor=TreeView;//修正constructor
var view=new TreeView();//view.__proto__=TreeView.prototype 自動完成
alert(view instanceof View); //true 查找到view.__proto__.__proto__時找到
alert(view instanceof TreeView); //true 查找到view.__proto__時找到
alert(Myinstanceof(view,View)); //true
alert(Myinstanceof(view,TreeView)); //true