[WorldMaker]

Note that constructorFunction.prototype predates __proto__ in the official specs (and also `class` notation) and is the oldest bit of object-oriented programming support in JS.

__proto__ on objects was originally a leaky abstraction in a specific browser. It caught on such that other browsers borrowed it, because they unfortunately had to, but the specs and the browsers all consider it deprecated and warn not to use it: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

(The standards compliant way to get an object's prototype at runtime is Object.getPrototypeOf(obj), and to change an object's prototype instance at runtime is Object.setPrototypeOf(obj, newPrototype).)

[kenbellows]

Very good points. And thanks for the note about Object.getPrototypeOf(obj) and Object.setPrototypeOf(obj, newPrototype), I don't think I had ever actually looked that up!