javascript-pour-les-jedis-episode-3-snippet-03.js

function Jedi() {}
Jedi.prototype.useForce = function () {
 console.log('I am using the force!');
};

const anakin = Jedi();
const luke = new Jedi();
console.log(anakin instanceof Jedi); //=> false
console.log(typeof anakin.useForce); //=> TypeError: anakin is undefined
console.log(luke instanceof Jedi); //=> true
console.log(typeof luke.useForce); //=> 'function'