reuseIdentifier
A string used to identify a reusable header or footer.
Declaration
var reuseIdentifier: String? { get }Discussion
You assign a reuse identifier to a header or footer view at creation time. Once assigned, the table view uses that reuse identifier to gather your views when they’re scrolled offscreen and queue them for later reuse. You can retrieve header or footer views by passing the same reuse identifier to the dequeueReusableHeaderFooterView(withIdentifier:) method of the table view.