あなたがJavaScriptを嫌いになるのに十分なコード

this.js

function Class (bar) {
  this.foo = bar;
}

Class.prototype.method = function () {
  return this.foo;
};

var instance = new Class('baz'),
    func = (function () {
        return function () {
            return instance.method();
        }
    })();

console.log(instance.method());
console.log(func());