Question

I need to use the Date object for three different purposes, can I do this as follows?

I am very new to JavaScript, so I am not sure if the following define is OK for all the browsers.

Date.prototype.yyyymmdd = function() 
{
  var yyyy = this.getFullYear().toString();    
  var mm = (this.getMonth()+1).toString(); 
  var dd  = this.getDate().toString();    
  return yyyy+"-" + (mm[1]?mm:"0"+mm[0])+"-" + (dd[1]?dd:"0"+dd[0]); 

}; 

Date.prototype.mmddyyyy = function() 
{
  var yyyy = this.getFullYear().toString();    
  var mm = (this.getMonth()+1).toString(); 
  var dd  = this.getDate().toString();    

  return (mm[1]?mm:"0"+mm[0])+"-" + (dd[1]?dd:"0"+dd[0])+"-" + yyyy; 
}; 

Date.prototype.mmdd = function() 
{
   var yyyy = this.getFullYear().toString();    
   var mm = (this.getMonth()+1).toString(); 
   var dd  = this.getDate().toString();    
   return (mm[1]?mm:mm[0])+"/" + (dd[1]?dd:dd[0]);
};


var d0 = new Date();
console.log(d0.mmddyyyy);

var d1 = new Date();
console.log(d1.yyyymmdd);

var d2 = new Date();
console.log(d2.mmdd);

Answer 1

You just missed the brackets – it should run in any browser (but will currently fail if console is not supported or in IE8, open)

DEMO

var d0 = new Date();
console.log(d0.mmddyyyy());

var d1 = new Date();
console.log(d1.yyyymmdd());

var d2 = new Date();
console.log(d2.mmdd());

I would personally prefer one prototype

DEMO:

Date.prototype.formatDate=function(fmt) {
  fmt = fmt || "yyyymmdd";
  var yyyy = this.getFullYear();    
  var mm = this.getMonth()+1;
  if (mm<10) mm="0"+mm;
  var dd  = this.getDate();    
  if (dd<10) dd="0"+dd;  
  if (fmt==="yyyymmdd") return yyyy+"-" + mm+"-" + dd;
  if (fmt==="mmddyyyy") return ""+mm+"-" + dd +"-" + yyyy;
  if (fmt==="mmdd")  return ""+mm+"/"+dd;
};


var d0 = new Date();
console.log(d0.formatDate("mmddyyyy"));
console.log(d0.formatDate("yyyymmdd"));
console.log(d0.formatDate("mmdd"));