var parent = {

  get: function fn() {

    return this.val;  

  },

  val: 42

};

​

var child = Object.create(parent);

child.val = 3.14159;

​

var grandchild = Object.create(child);

​

console.log(parent.get()); // 42

console.log(child.get()); // 3.14159

console.log(grandchild.get()); // 3.14159

​