var c = {    name: 'The c object',    log: function() {        this.name = 'Updated c object';        console.log(this);        var setname = function(newname) {            this.name = newname;            console.log(this);        }        setname('Updated again! The c object');        console.log(this);    }}c.log();第二個console.log為什么是指向window？？？