Why is it necessary to set the prototype constructor?

Question

In the section about inheritance in the MDN article Introduction to Object Oriented Javascript, I noticed they set the prototype.constructor:

// correct the          


        

Answer 1

Got a nice code example of why it is really necessary to set the prototype constructor..

function CarFactory(name){ 
   this.name=name;  
} 
CarFactory.prototype.CreateNewCar = function(){ 
    return new this.constructor("New Car "+ this.name); 
} 
CarFactory.prototype.toString=function(){ 
    return 'Car Factory ' + this.name;
} 

AudiFactory.prototype = new CarFactory();      // Here's where the inheritance occurs 
AudiFactory.prototype.constructor=AudiFactory;       // Otherwise instances of Audi would have a constructor of Car 

function AudiFactory(name){ 
    this.name=name;
} 

AudiFactory.prototype.toString=function(){ 
    return 'Audi Factory ' + this.name;
} 

var myAudiFactory = new AudiFactory('');
  alert('Hay your new ' + myAudiFactory + ' is ready.. Start Producing new audi cars !!! ');            

var newCar =  myAudiFactory.CreateNewCar(); // calls a method inherited from CarFactory 
alert(newCar); 

/*
Without resetting prototype constructor back to instance, new cars will not come from New Audi factory, Instead it will come from car factory ( base class )..   Dont we want our new car from Audi factory ???? 
*/