# EntityCollection An ordered, mutable collection of entities. ``` protocol EntityCollection : Collection where Self.Element == Entity, Self.Index == Int ``` ## Topics ### Instance Methods [`func append(Entity)`](/documentation/RealityKit/EntityCollection/append(_:)) Adds the specified entity to the end of this collection. [`func append(contentsOf: S)`](/documentation/RealityKit/EntityCollection/append(contentsOf:)) Adds the specified sequence of entities to the end of this collection, in order. [`func insert(Entity, beforeIndex: Int)`](/documentation/RealityKit/EntityCollection/insert(_:beforeIndex:)) Adds the specified entity to this collection directly before the entity at the given index. If the entity is already located before the index, the collection will not change. [`func insert(contentsOf: S, beforeIndex: Int)`](/documentation/RealityKit/EntityCollection/insert(contentsOf:beforeIndex:)) Adds the specified sequence of entities to this collection in order, directly before the entity at the given index. [`func remove(Entity)`](/documentation/RealityKit/EntityCollection/remove(_:)) Removes the entity from the collection. [`func remove(at: Int)`](/documentation/RealityKit/EntityCollection/remove(at:)) Removes the entity at the given index from this collection. [`func removeAll()`](/documentation/RealityKit/EntityCollection/removeAll()) Removes all entities from this collection. [`func removeAll(where: (Entity) throws -> Bool) rethrows`](/documentation/RealityKit/EntityCollection/removeAll(where:)) Removes all entities from this collection that satisfy the given predicate. [`func replaceAll(S)`](/documentation/RealityKit/EntityCollection/replaceAll(_:)) Replaces all entities in this collection with those from the given sequence. ## Relationships ### Inherits From [`Sequence`](/documentation/Swift/Sequence) [`Collection`](/documentation/Swift/Collection) ### Conforming Types [`RealityViewEntityCollection`](/documentation/RealityKit/RealityViewEntityCollection) [`ChildCollection`](/documentation/RealityKit/Entity/ChildCollection) [`EntityCollection`](/documentation/RealityKit/RealityRenderer/EntityCollection) --- 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)