SectionIndexTitles for a UICollectionView

Question

So I implemented a proper TableView with a search functionality and sectionIndexTitles. Now, I am trying to implement a UICollectionView

Answer 1

You can now simply use (as of iOS 10.3)

optional func indexTitles(for collectionView: UICollectionView) -> [String]?

Which expects an array like: ['A', 'B' ,'C'] as its return value.