Javascript Date toMyDateString()

Date.prototype.toMyDateString=function(){
 var year=this.getFullYear();
 var month=this.getMonth();
 var date=this.getDate();

 return year+"-"+month+"-"+date;
}
String.prototype.dateStringToDate=function(text){
 console.log(this);/* ww w  .  ja v a  2s.  co  m*/
}
var s="I am fudongdong";

s.dateStringToDate();

var d=new Date();
console.log(d.toMyDateString());