# Using getters and setters Part 3

Here is the final Part 3 post on getters and setters. This is more refined and considered the goto method.

%[https://gist.github.com/anjanesh/18630fc3f7b1684569fc6ad34c45a883] 

Here, the USD price is pre-defined as usual as `price_USD`.

The key takeaway is in this line :

```javascript
const addINRPrice = (product) => Object.defineProperty(product, 'price_INR', INRPriceConverter);
```

`price_INR` is defined as a property in the `products` array of objects by setting it in `Object.defineProperty`. As you can see, there are 3 arguments to this :

1. the `product`, which is the parameter in `addINRPrice` method.
    
2. The other property `price_INR` which we had declared in the `products` array explicitly in the first two parts of this blog series, is now dynamically added.
    
3. The method that is used to set and get the dynamically added property `price_INR`.
    

`this.products.map(addINRPrice);` adds the `price_INR` property to each of the objects in the `products` array.

In AlpineJS store's `init()` method which does some initialisation, a method `INRPriceConverter` is defined that has a setter and a getter to convert / return USD or INR values.

Let's see what the setter and getter in `INRPriceConverter` does.

The getter is straight-forward - `return this.price_USD * 83;` returns the INR value when the USD value is multiplied by 83.

Now the setter which has a parameter `val` in `this.price_USD = val / 83;` - here, `val` is `price_INR` (that's added dynamically) and calculated to it's USD value.

Demo : [https://anjanesh.s3.amazonaws.com/demo/alpine/alpine-auto-update-variable-method-2.html](https://anjanesh.s3.amazonaws.com/demo/alpine/alpine-auto-update-variable-method-2.html)