Design Pattern - Factory

design-pattern-factory.js

var Mobile = function(size) {
  this.displaySize = size;
};

var Tablet = function(size) {
  this.displaySize = size;
};

var Desktop = function(size) {
  this.displaySize = size;
};

// Factory which will create different types of objects based on requirement
var DeviceFactory = function(){
  var device;
  this.createDevice = function(size) {
    switch(size) {
      case 'small':
        return new Mobile(size);
      case 'medium':
        return new Tablet(size);
      case 'large':
        return new Desktop(size);
    }
  }
};

var factory = new DeviceFactory();
var device1 = factory.createDevice('small');
var device2 = factory.createDevice('medium');
var device3 = factory.createDevice('large');

console.log(device1.displaySize);   //  small
console.log(device2.displaySize);   //  medium
console.log(device3.displaySize);   //  large