Javascript - Object Constructor

object.js

// Object Constructor
function Car(){
    // private variable
    var speed = 0;
    
    // public methods
    return {                
               accelrate : function(s){
                    speed = speed + s;
                   
               },
        
               desaccelerate : function (s){
                   speed = speed - s;
                 
               },
        
               getSpeed : function(){
                  return speed;
               }

           }
}

var car1 = new Car();
car1.accelrate(10);
car1.accelrate(10);
console.log(car1.getSpeed());

var car2 = new Car();
car2.accelrate(5);
car2.accelrate(10);
car2.getSpeed();
console.log(car2.getSpeed());