NSArray — Mac OS X 10.0
This class manages an immutable ordered collection of
Objects are stored in an array by reference. That is, the pointer to
the object is stored rather than the object itself. When the object
is added to an array, the array retains it by sending a
retain message to the object. When the array is
released it sends a
release message to each of its
There are many methods for querying the contents of the array.
objectAtIndex: is commonly used to
access an object at some position in the array. Conversely, we can
determine the index of some object using the method
indexOfObject:, which returns the lowest index of
the member that is equivalent the specified object. To determine the
number of objects contained within the array the
count method is invoked.
To enumerate the contents of an array, create
NSEnumerator object for the array using one of
reverseObjectEnumerator. A standard object
enumerator will return the objects in the order that they exist
within the array, while the reverse enumerator will return members
starting from the last object and working its way forward. See the
NSEnumerator class description for more
information on enumerating collections.
Often we want to invoke some method in each member of a collection.
NSArray provides a method that saves us from the
burden of having to enumerate the contents of the array and send the
message manually. This method is