以下几段代码，输出的结果不一样。希望有大神可以解答一下原理，谢谢！

var myvar = "TheWindow"; var object = {     myvar : "MyObject",     getVar : function(){         return function(){             return myvar;         };     } }; console.log(object.getVar()());//输出TheWindow  function MyCont(){     var myvar = "MyObject";     this.getVar = function(){         return function(){             return myvar;         };     } } var obj = new MyCont(); console.log(obj.getVar()());//输出MyObject

然后我修改了一下，加上了this，输出结果又不同了。

var myvar = "TheWindow"; var object = {     myvar : "MyObject",     getVar : function(){         return function(){             return this.myvar;//此处加入了this，依旧输出TheWindow         };     } }; console.log(object.getVar()()); function MyCont(){     var myvar = "MyObject";     this.getVar = function(){         return function(){             return this.myvar;//此处加入了this，输出变成了TheWindow，而不是原先的MyObject         };     } } var obj = new MyCont(); console.log(obj.getVar()());

然后我再改一下

var myvar = "TheWindow"; var object = {     myvar1 : "MyObject",     getVar : function(){         return function(){             return myvar1;//虽然object内含有myvar1属性，但是这样写会报错,但是如果写this.myvar1的话就不报错，输出undefined         };     } }; console.log(object.getVar()());   var myvar = "TheWindow"; var object = {     myvar : "MyObject",     getVar : function(){           return myvar;//此处去掉了function，还是输出TheWindow     } }; console.log(object.getVar());   var myvar = "TheWindow"; var object = {     myvar : "MyObject",     getVar : function(){           return this.myvar;//对比上面，加入了this，则输出的是对象属性MyObject     } }; console.log(object.getVar()); 

最后还是要感谢一下，好心人帮忙解答问题，万分感谢！