Why *not* “inherit”/extend from Object in JavaScript?

Question

It is well-known that declaring objects with JSON notation makes them \"inherit\" from (or, more precisely, to be built like) the base Object:

myobj={a:1, b:2};

Answer 1

Instead of this:

myobj = Object.create(Object);

...I think you mean this is the equivalent:

myobj = Object.create(Object.prototype);

...because:

Object.getPrototypeOf( {a:1, b:2} ) === Object.prototype;  // true

---

As to why to use null early, if your object has no need for any of the properties of Object.prototype, ending the chain early would technically (though marginally) speed up property lookups when a property does not exist on the object in question.

Note that I say "early" because the chain always ends with null.

Object.getPrototypeOf( Object.prototype );  // null

---

             obj ----------> proto -------> Object.proto -----> null
         +---------+      +---------+      +-------------+     
         |         |      |         |      |             |
         |  foo:1  |      |  bar:1  |      | toString:fn |      null
         |         |      |         |      |             |
         +---------+      +---------+      +-------------+ 
              ^                ^                  ^               X
              |                |                  |               |
obj.foo ------+                |                  |               |
              ^                |                  |               |
obj.bar-------+----------------+                  |               |
              ^                ^                  |               |
obj.toString--+----------------+------------------+               |
              ^                ^                  ^               |
obj.baz-------+----------------+------------------+---------------+

   ^---property lookups

Notice that the baz property does not exist anywhere in the prototype chain.

Because of this, it needs to search each object in sequence until it finally reaches null before it realizes that baz doesn't exist anywhere.

If you eliminate the Object.prototype from the chain, it will get to null a little quicker.