闭包中的this

Question

varname="thewindow";
varobject={
name:"myobject";
getName:function(){
returnthis.name;
}
};
object.getName();//"myobject"
(object.getName)();//"myobject"
(object.getName=object.getName)();//"thewindow"
第二和第三个输出为什么不一样，尤其是第三个，怎么理解？