1 var book={}; 2 Object.defineProperties(book,{ 3     _year:{ 4         value:2014 5     }, 6     edition:{ 7         value:1 8     }, 9     year:{10         get:function(){11             return this._year;12         },13         set:function(newValue){14             if(newValue>2014){15                 this._year=newValue;16                 this.edition+=newValue-2014;17             }18         }19     }20 });