Question

I would like a kind of wrapper for the default Date object in JavaScript so that whenever I have something like var a = new Date();, I want to execute some particular code in the constructor.

I basically want to have my own Date class that needs to be invoked whenever a call is made to Date() rather than the native code.

Answer 1

You need to save the reference for the native Date object, than make your own wrapper, which invokes the native Date then mutates it, or adds additional behavior.

var OldDate = Date;
var Date = function() {
  var that = new OldDate();
  that.mystuff = 5;
  // do other things with the date
  // and execute your own things
  // ...
  return that;
}

var now = new Date();
alert(now.mystuff);

However, I wouldn’t mess with native objects.