Code:

  <script>
            function Dog(){}
            var dog = new Dog();
            var dog1 = Object.create(dog);
            // console.log(dog1._proto_);
            console.log(Object.getPrototypeOf(dog1));
   </script>
        

code, so the prototype of the instance dog1 should be dog. But two problems were encountered in the actual testing:

1. console.log (dog1._proto_) outputs undefined. After Baidu, I saw a lot of saying that _ proto_ is a non-standard usage, which is not recommended until after es6, but the browser (I am using the latest version of chrome) should be parsable. Why output undefined?

2. So I switched to getPrototypeOf, but the output was not the prototype dog of dog1, but the constructor Dog.

confused about the above two points, solve