Functional inheritance

functional-inheritance.js

function car() {
  return {
    start: function() {
      console.log("Engine on.")
    },
    accelerate: function() {
      console.log("Let's go!")
    }
  }
}

function roadster(brand) {
  var brand = brand
  var self = car()

  self.setBrand = function(name) {
    brand = name
  }
  self.getBrand = function() {
    console.log(brand)
  }
  return Object.freeze(self)
}

var myCar = roadster("Porsche")
myCar.start()            // "Engine on."
myCar.getBrand()         // "Porsche"
myCar.setBrand("Jaguar")
myCar.getBrand()         // "Jaguar"

I, too, really like this approach and was curious about the memory and performance so I forked to add some tests. You should be able to clone and run the commands in the comment to play with it yourself.

I found that using prototypical inheritance and new was 10x faster and used less memory. For a thousand roadsters, Crockford's new approach used ~387 KB more memory (at 10,000 it used over 2 MB more). I'm not super confident in how I compared memory usage so if you have any feedback, I'd appreciate it.

Do the pro's of "nicer" code outweigh the con's of KB and MB of inefficiencies?