inherits_1.js

function Human() { this.speak = function() { return "bonjour" } }
function Monster() { this.speak = function() { return "grrrr" } }

function Hulk() {}

// hulk inherits from Human
Hulk.prototype = new Human()
hulk1 = new Hulk()
hulk1.speak()
=> "bonjour"

// hulk inherits from Monster
Hulk.prototype = new Monster()
hulk2 = new Hulk()
hulk2.speak()
=> "grrrr"

// warning:
hulk1.speak()
=> "bonjour"