Use the documentation in Swift Playgrounds on iPad
In Swift Playgrounds, you can access the Swift developer documentation—a collection of articles and reference information about the iOS Software Development Kit. It documents the technologies and tools available on iOS and iPadOS for creating games, graphics, user interfaces, and more.
Open the Swift documentation
In the Swift Playgrounds app
on your iPad, open a playground, tap 
in the upper-right corner of the coding area, then tap Documentation.The documentation opens on the right side of the screen. To expand it to full screen, drag the resize handle to the left.
You can browse the topics and tap one to read it, or you can tap
to search for topics.
Navigate the Swift documentation
In the Swift Playgrounds app
on your iPad, tap highlighted text in the documentation’s table of contents or in the articles to follow links to related topics, learn about properties and classes, and so on.As you explore topics, a path (called a jump bar) appears at the top of the page, showing the pages you visited.
To see a list of related topics you can jump to, tap an element in the jump bar.
To close the documentation, tap 
.