Functional instantiation

var makeCat = function(){
  var cat = {};
  cat.stomach = [];
  
  cat.meow = function(){
    console.log("MEOW");
  };
  
  cat.eat = function(food){
    cat.stomach.push(food);
  };
  return cat;
};

var kitty = makeCat();
kitty.meow(); // "MEOW"

kitty.eat('mouse');
console.log(kitty.stomach); // ["mouse"]

kitty.eat('owner');
console.log(kitty.stomach); // ["mouse", "owner"]