//用setTimeout模仿setInterval

var MyInterVal = function(fun,tm){

    if(this == window){

        return new MyInterVal(fun,tm);

    }
　　this.Fun = null;

    this.id = -1;this.clear = function(id){

        clearTimeout(this.id);

    }

    this.setInterval = function(_fun,_tm){

        var self = this;

        if(this.Fun==null){

            if(typeof _fun=="string"){

                this.Fun = new Function(_fun);

            }else if(typeof _fun=='function'){

                this.Fun = _fun;

            }

        }

        this.id = setTimeout(function(){

            self.Fun();

            self.setInterval(self.Fun,_tm);

        },tm);

    }

    this.setInterval(fun,tm);

}

//使用方法一

var s = MyInterVal(function(){

    console.log();

},);

//使用方法二

var s = MyInterVal("console.log(1)",1000)

setTimeout(function(){

    s.clear();//清除

},)