CODEWITHSUNDEEP
iosuitableviewuicollectionview
Satyam
Satyam

Reputation: 15894

Difference in collection view & table view methods

UICollectionView has a method indexPathsForVisibleItems that returns array of index paths. Where as UITableView has similar method indexPathsForVisibleRows that also returns array of index paths, buts its an optional. Why is there a difference between 2 similar methods from Apple itself?

Upvotes: 0

Views: 433

Answers (1)

rmaddy
rmaddy

Reputation: 318774

Because Apple developers aren't perfect and they aren't always consistent.

UITableView has been around since iOS 2.0 and someone decided back in 2008 to return nil if there were no visible rows.

UICollectionView was added years later in iOS 6.0 and someone decided to return an empty array instead of nil if there were no visible rows.

Of course this was all in Objective-C. When Swift came along, it meant that UITableView indexPathsForVisibleRows needed to be optional since the Objective-C property could be nil.

BTW - In macOS, NSCollectionView indexPathsForVisibleItems is a function instead of a property and it is a set, not an array. Again, inconsistent.

Upvotes: 1

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