> For the complete documentation index, see [llms.txt](https://attr.sygnal.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://attr.sygnal.com/sa5-data/advanced-use.md).

# Advanced Use

## Grouping & Group Counts

## Example

Scenario;

> You have a CMS collection of Locations, which each have a State. You want to show a list of States, with the count of Locations in each. 

Let's suppose you have setup this SA5 Data source.

<figure><img src="/files/7DnmCfcEWLH7RpC84yKU" alt=""><figcaption></figcaption></figure>

Once loaded, the data it will exist as a JavaScript Map in SA5's Datastore;

```javascript
ds.store.locations.data
```

You can transform that Map into a new map which contains Groups and counts, like this;

```javascript
// Get count of locations in each state
let result = new Map();
ds.store.locations.data.forEach(({ state }) => {
    result.set(state, (result.get(state) || 0) + 1); // increment state count
});
```

Now you can use your result Map however you like.&#x20;