Object.createを使わないクラスの継承

gistfile1.js

function ObjectCreate(o) {
  function F() {}
  F.prototype = o;
  return new F();
}

function Parent(text) {
  console.log('called parent');
  this.text = text || 'default text';
}

function Child(text) {
  Parent.call(this, text);
}
Child.prototype = ObjectCreate(Parent.prototype);

var c = new Child('child text!');
console.log(c.text);