JSFiddle - React, Tailwind, and code Playground

JavaScript

function Car(){
    var miles = 0;    
    
    function drive(dist){
        miles = miles+dist;
    }
    return {
        drive:drive,
        milesA:miles,
        milesB:function(){
            return miles;
        }
    }          
}

var car = new Car;

car.drive(50);
//car.milesA= 25;

alert(car.milesA );
alert(car.milesB() );