An abstract class whose subclasses enumerate collections of objects, such as arrays and dictionaries.


All creation methods are defined in the collection classes—such as NSArray, NSSet, and NSDictionary—which provide special NSEnumerator objects with which to enumerate their contents. For example, NSArray has two methods that return an NSEnumerator object: objectEnumerator() and reverseObjectEnumerator(). NSDictionary also has two methods that return an NSEnumerator object: keyEnumerator() and objectEnumerator(). These methods let you enumerate the contents of a dictionary by key or by value, respectively.

You send nextObject() repeatedly to a newly created NSEnumerator object to have it return the next object in the original collection. When the collection is exhausted, nil is returned. You cannot “reset” an enumerator after it has exhausted its collection. To enumerate a collection again, you need a new enumerator.

The enumerator subclasses used by NSArray, NSDictionary, and NSSet retain the collection during enumeration. When the enumeration is exhausted, the collection is released.


Getting the Enumerated Objects

var allObjects: [Any]

The array of unenumerated objects.

func nextObject()

Returns the next object from the collection being enumerated.

Instance Methods

func makeIterator()

Return an iterator over the enumerator.

See Also


protocol NSFastEnumeration

A protocol that objects adopt to support fast enumeration.

struct NSIndexSetIterator

An iterator suitable for enumerating the elements of an index set.

struct NSEnumerationOptions

Options for block enumeration operations.

struct NSSortOptions

Options for block sorting operations.