Why can't I modify the constructor function from prototype

The following code is available:

function Rabbit () {var jumps = "yes";};                    var rabbit = new Rabbit (); alert (rabbit.jumps);    Undefinedalert (Rabbit.prototype.constructor); Outputs exactly the code of the function Rabbit ();

Change to this:

Rabbit.prototype.constructor = function Rabbit () {this.jumps = "no";};    alert (Rabbit.prototype.constructor);             Again outputs the Code of Function Rabbit () and with new this.jumps = "no"; var rabbit2 = new Rabbit ();                   Create new object with new Constructoralert (Rabbit2.jumps); But still outputs undefined

Why is jumps still undefined?

That's because:

Rabbit.prototype.constructor is simply a reference to the original constructor, which is used to detect its constructor when the class is instantiated. So, if you try:

Rabbit.prototype.constructor = function Rabbit () {this.jumps = "no";};

You just broke the reference on the prototype object to the original object constructor. So you can't change the original constructor.

Why can't I modify the constructor function from prototype