Javascript subclassing pattern using prototypes

javascript-subclassing-pattern

//Super class
var Car = function(loc){
  this.loc=loc;
};

Car.prototype.move=function(){
  this.loc++;
};

//Sub class
var Van = function (loc){
  Car.call(this.loc);
}
Van.prototype=Object.create(Car.prototype);
Van.prototype.constructor=Van;
Van.prototype.grab=function(){
  //whatever
}


var zed = new Car(3);
zed.move();

var amy=new Van(9);
amy.move();
amy.grab();