setTimeout() & setInterval() 作用域

setTimeout() 和 setInterval() 调用的代码或者函数是全局作用域的

要传递this通过匿名函数来实现：

 

var show = function(){
            alert(this+" is all");
        }
        var Obj = function(){
            this.show = function(){
                alert(this+" is obj");
            }
            this.time = function(){
                var self = this;
                //setTimeout(function(){this.show();}, 2000);//window is all
                setTimeout(function(){self.show();}, 2000);//Obj is obj
                //setTimeout("this.show()", 2000);//window is all
                //setTimeout("self.show()", 2000);//window is all
                //setTimeout(this.show, 2000);//window is obj
                //setTimeout(self.show, 2000);//window is obj
            }
        }
        var obj = new Obj();
        obj.time();