Question

I have the following CoffeeScript code:

planet = new Planet p5, {x: 100, y: 100, diameter: 20}

and somewhere else:

class GameObject
  constructor: (@p5, @x, @y) ->
    @selected = false

class Planet extends GameObject
  constructor: (p5, opts) ->
    super (p5 opts.x opts.y)
    @diameter = opts.diameter

and for the super line it says:

Uncaught TypeError: Property ‘x’ of object #< Object> is not a function

and it was ok when it was just:

class Planet
  constructor: (p5, opts) ->
    @x = opts.x
    @y = opts.y
    @diameter = opts.diameter
    @selected = false

i.e. before making it a child of a more generic GameObject… I have tried some rearrangements to make it work, but all invain. Not sure if it relates to CoffeeScript or JavaScript. The “try CoffeScript” thing on the official website spots no errors here. Browser is Chrome… What is wrong here and how do I overcome this?

Answer 1

You’re missing commas to separate the arguments:

super (p5 opts.x opts.y)

should be

super (p5, opts.x, opts.y)

Otherwise, that line is interpreted as super(p5(opts.x(opts.y))), hence the “not a function” error.