# itemForFeatureCollection(itemCollection, geoJSON) Overrides a feature collection. ``` itemForFeatureCollection?( itemCollection: ItemCollection, geoJSON: D, ): ItemCollection | Item[] | null; ``` ## Parameters `itemCollection` A collection containing associated annotations and overlays. `geoJSON` The original GeoJSON object for the `FeatureCollection`. This contains an array of `feature` types. ## Return Value A map item or an array of map items. ## Discussion MapKit JS calls this method for every GeoJSON `FeatureCollection` object. The framework also calls this method after constructing subitems and calling their delegate functions. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)