Enterprise Objects Framework Release 1.0 Copyright ©1994 by NeXT Computer, Inc.  All Rights Reserved.


Inherits From: NSObject
Declared In: foundation/NSUtilities.h

Class Description

NSEnumerator is a simple abstract class whose instances enumerate collections of other objects. Collection objects -- such as arrays and dictionaries -- provide special NSEnumerator objects with which to enumerate their contents. You send nextObject repeatedly to the NSEnumerator object to have it return the next object in the original collection until nil is encountered.

Collection classes such as NSArray and NSDictionary include methods that return an enumerator appropriate to the type of collection. NSArray has two methods that return an NSEnumerator object, objectEnumerator and reverseObjectEnumerator (the former traverses the array starting at base zero, while the other starts with the last object in the array and works down). NSDictionary has two enumerator-providing methods: keyEnumerator and objectEnumerator.

Note:  Enumeration through mutable collections is not safe if the original collection is modified.

Instance Variables

None declared in this class.

Method Types

Getting the next object nextObject:

Instance Methods


Returns the next object in the enumeration object (which can be an array, dictionary, or similar object). When nextObject returns nil, the enumeration object has been traversed. The following code illustrates how this might work:

NSEnumerator *enumerator = [anArray objectEnumerator];
id object;
while (object = [enumerator nextObject]) {
// do something with object...