JavaScript Classes

A class is a type, or category, of objects. Technically speaking, Javascript doesn't recognize the idea of "classes", but they can be emulated.

You define a class using an object constructor.

function Song(name, year, timesPlayed) {
  this.name = name;
  this.yearRecorded = year;
  this.timesPlayed = timesPlayed;
}

You then create objects of this class, using the constructor...

var WildThing = new Song("Wild Thing", 1966, 30);
var MaggotBrain = new Song("Maggot Brain", 1972, 35);

Characteristics of objects can then be brought up by evoking a method...

Song.prototype.announce = function(){
    alert("The next song to be played is" + this.name);
}

A prototype extends a class with additional functionality that is available for all objects of that class.