So far, the ViewController class has implemented the UITableViewDelegate protocol but none of the delegate methods have been implemented yet. Any time certain interactions occur on a table view, such as tapping a cell or swiping on a cell, the table view will attempt to call the corresponding delegate methods to inform the delegate about the action that occurred.

The UITableViewDelegate protocol does not specify any required methods, which is why it has been possible to conform to this protocol without actually doing work. Usually, you will want to implement at least one method from UITableViewDelegate because simply displaying a list without responding to any interactions is quite boring. Let's go ahead and explore some of the methods from UITableViewDelegate to create a better experience for Hello-Contacts. If you take a look at the documentation for UITableViewDelegate, you'll notice that it has a large collection of delegate methods that you can implement in your app.

The documentation for UITableViewDelegate lists methods for configuring cell height, content-indentation level, cell-selection, and more. There are also methods that you can implement to get notified when the table view is about to display a cell or is about to stop displaying one. You can handle cell-selection, cell-highlighting, reordering cells, and even deleting them. One of the more common methods to implement is tableView(_:didSelectRowAt:). After you have implemented this method, you'll also implement cell-reordering and -removal.