> For the complete documentation index, see [llms.txt](https://docs.mapbox.com/mapbox-gl-js/ja/llms.txt)
# Change the case of labels
Use the [`upcase`](https://docs.mapbox.com/style-spec/reference/expressions/#upcase) and [`downcase`](https://docs.mapbox.com/style-spec/reference/expressions/#downcase) expressions to change the case of labels.
> Example code:
**JavaScript**
```html
Change the case of labels
```
**React**
```jsx
import React, { useEffect, useRef } from 'react';
import * as mapboxgl from 'mapbox-gl/esm';
import 'mapbox-gl/dist/mapbox-gl.css';
const MapboxExample = () => {
const mapContainerRef = useRef();
const mapRef = useRef();
useEffect(() => {
mapRef.current = new mapboxgl.Map({
// TO MAKE THE MAP APPEAR YOU MUST
// ADD YOUR ACCESS TOKEN FROM
// https://account.mapbox.com
accessToken: 'YOUR_MAPBOX_ACCESS_TOKEN',
container: mapContainerRef.current,
style: 'mapbox://styles/mapbox/standard', // style URL
center: [-116.231, 43.604],
zoom: 11
});
mapRef.current.on('load', () => {
mapRef.current.addSource('off-leash-areas', {
type: 'geojson',
data: 'https://docs.mapbox.com/mapbox-gl-js/assets/boise.geojson'
});
mapRef.current.addLayer({
id: 'off-leash-areas',
type: 'symbol',
source: 'off-leash-areas',
layout: {
'text-field': [
'format',
['upcase', ['get', 'FacilityName']],
{ 'font-scale': 0.8 },
'\n',
{},
['downcase', ['get', 'Comments']],
{ 'font-scale': 0.6 }
],
'text-font': ['Open Sans Semibold', 'Arial Unicode MS Bold']
}
});
});
}, []);
return ;
};
export default MapboxExample;
```