<!--
{
  "documentType" : "article",
  "framework" : "Foundation",
  "identifier" : "/documentation/Foundation/NSSet/Sequence-Implementations",
  "metadataVersion" : "0.1.0",
  "role" : "collectionGroup",
  "title" : "Sequence Implementations"
}
-->

# Sequence Implementations

## Topics

### Instance Properties

[`var underestimatedCount: Int`](/documentation/Foundation/NSSet/underestimatedCount)

A value less than or equal to the number of elements in the collection.

### Instance Methods

[`func makeIterator() -> NSFastEnumerationIterator`](/documentation/Foundation/NSSet/makeIterator())

Return an *iterator* over the elements of this *sequence*.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)