> For the complete documentation index, see [llms.txt](https://docs.mapbox.com/mapbox-gl-js/llms.txt)
# Display line that crosses 180th meridian
Draw a line across the 180th meridian using a [GeoJSON source](https://docs.mapbox.com/style-spec/reference/sources/#geojson).
> Example code:
**JavaScript**
```html
Display line that crosses 180th meridian
```
**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',
center: [139.839478, 35.652832],
zoom: 2
});
mapRef.current.on('load', () => {
mapRef.current.addLayer({
id: 'route',
type: 'line',
source: {
type: 'geojson',
data: {
type: 'Feature',
properties: {},
geometry: createGeometry(false)
}
},
layout: { 'line-cap': 'round' },
paint: {
'line-color': '#007296',
'line-width': 4
}
});
mapRef.current.addLayer({
id: 'route-label',
type: 'symbol',
source: 'route',
layout: {
'symbol-placement': 'line-center',
'text-field': 'Crosses the world'
}
});
mapRef.current.addLayer({
id: 'route-two',
type: 'line',
source: {
type: 'geojson',
data: {
type: 'Feature',
properties: {},
geometry: createGeometry(true)
}
},
layout: { 'line-cap': 'round' },
paint: {
'line-color': '#F06317',
'line-width': 4
}
});
mapRef.current.addLayer({
id: 'route-two-label',
type: 'symbol',
source: 'route-two',
layout: {
'symbol-placement': 'line-center',
'text-field': 'Crosses 180th meridian'
}
});
function createGeometry(doesCrossAntimeridian) {
const geometry = {
type: 'LineString',
coordinates: [
[-72.42187, -16.59408],
[140.27343, 35.67514]
]
};
// To draw a line across the 180th meridian,
// if the longitude of the second point minus
// the longitude of original (or previous) point is >= 180,
// subtract 360 from the longitude of the second point.
// If it is less than 180, add 360 to the second point.
if (doesCrossAntimeridian) {
const startLng = geometry.coordinates[0][0];
const endLng = geometry.coordinates[1][0];
if (endLng - startLng >= 180) {
geometry.coordinates[1][0] -= 360;
} else if (endLng - startLng < 180) {
geometry.coordinates[1][0] += 360;
}
}
return geometry;
}
});
return () => {
mapRef.current.remove();
};
}, []);
return ;
};
export default MapboxExample;
```