Performance overhead: Using NSEnumerator involves creating an object to represent the enumeration and calling a method on it for every single iteration. This incurs message send overhead for each iteration, which can be inefficient, especially for large collections[1][2].
Lack of language support: NSEnumerator uses a separate object and method calls to perform enumeration, which is not as tightly integrated with the language syntax compared to modern enumeration techniques[2].
To address these shortcomings, Apple introduced NSFastEnumeration in OS X Leopard and iOS 2.0. NSFastEnumeration provides a more efficient and convenient way to enumerate collections:
Reduced overhead: NSFastEnumeration leverages native language support to minimize message sends. It creates a struct to represent the enumeration state and repeatedly calls a single method (countByEnumeratingWithState:objects:count:) on the col...
