What is the end of prototype chain in javascript — null or Object.prototype?

Question

I\'ve been reading about prototype chain in JavaScript and came to two slightly different definitions. It is said that every object in JavaScript has a prototype and that pr

Answer 1

What is the end of prototype chain in javascript

Null. The only authority on the language is ECMA-262.

Are objects, which are not created from object literals, not linked to Object.prototype

They may or many not be, e.g.

var x = Object.create(null)

has a [[Prototype]] of null, whereas:

var y = {};

has a [[Prototype]] of Object.prototype.

Say I have an object var x = { len: 4, breadth: 5}. Would javascript automatically create it's proptotype x.prototype.

No. Function objects have default prototype objects. Plain objects have a default [[Prototype]] (i.e. internal prototype property) that is Object.prototype (unless constructed as above).

And how long would the prototype chain be? Would x.prototype have only one prototype Object.prototype making a 3 point chain?

Two values: Object.prototype and null.

How does javascript internally creates automatic prototypes?

However it likes, the language specification does not define implementation, only behaviour.