简单的JavaScript类封装实现类操作

想用JS实现类封装结构，根据红色警戒写了一个超小示例。

非常希望有高手提改进意见！以后扩充。

RA2.js

/***RA2***/

console.log("RA2");
var CountryGroup = Object.freeze({"A":"A","R":"R"});
//console.log(CountryGroup.R);
//console.log(Object.keys(CountryGroup)[CountryGroup.A]);

var TankType = Object.freeze({"CannonTank":"CannonTank","LightTank":"LightTank"});

var Country = function(name, countryGroup){
    
    var _name = name, 
        _countryGroup = countryGroup

    this.GetName = function(){return _name;}
    this.SetName = function(newName){_name = newName;}
    this.GetCountryGroup = function(){return _countryGroup;}
    this.SetCountryGroup = function(newCountryGroup){_countryGroup = newCountryGroup;}

    this.CreateHeavyFactory = function(){
        var heavyFactory = new HeavyFactory(this);
        return heavyFactory;
    }

}

var HeavyFactory = function(country){
    var _country = country

    this.GetCountry = function(){return _country;}
    this.SetCountry = function(newCountry){_country = newCountry;}

    this.CreateTank = function(country, tankType){
        var tank;
        switch(tankType){
            case TankType.CannonTank:
                tank = new CannonTank(country);
                break;
            default:
                tank = new LightTank(country);
                break;
        }
        
        return tank;
    }

}

var Tank = function(country){
    var _country = country

    this.Run = function(){}

    this.Fire = function(){}
}

var LightTank = function(country){
    Tank.call(this,country);

    this.Run = function(){console.log("fast run");}

    this.Fire = function(){console.log("common fire");}
}

var CannonTank = function(country){
    Tank.call(this,country);

    this.Run = function(){console.log("slow run");}

    this.Fire = function(){console.log("fast fire");}
}

调用方法示例：

<script type="text/javascript">

var c = new Country("CHN",CountryGroup.R);
var hf = c.CreateHeavyFactory(c);

var tankA = hf.CreateTank(c, TankType.CannonTank);
tankA.Run();
tankA.Fire();

var tankB = hf.CreateTank(c, TankType.LightTank);
tankB.Run();
tankB.Fire();

</script>