Javascript infinite prototype chain

问题

I am using the following test code:

function Test() {

 }

 Test.prototype.MyMethod =  {
    a: function() {

    },
    b: function() {

    }
 }

And to run it I'm simply doing:

var test = new Test();
console.debug(test);

In the firebug console, I expand the object that was printed and look inside of __proto__:

In there find a seemingly unending chain of constructor -> prototype:

+MyMethod
-constructor
  -prototype
     +MyMethod
     -constructor
        -prototype
           +MyMethod
           -constructor

and so on. Did I do something wrong here? Why does the prototype chain seem unending?

回答1:

prototypes have a property called constructor that refers to the function that owns the prototype.

This cycle is by design.

回答2:

The prototype's constructor refers back to itself, so as you 'unfold' it, you are just opening the same structure over and over again. It is not actually 'infinite.'

来源：https://stackoverflow.com/questions/4740849/javascript-infinite-prototype-chain