Managing Memory Using Retain and Release

Unlike in Java or C#, when programming for iOS, you manage memory manually; there is no garbage collection on iOS devices. Although as of OS X 10.5, Cocoa includes an option to use automatic garbage collection, this option is not available on iOS devices. Table 3-1 summarizes Objective-C’s memory management methods.

Table 3-1. NSObject Memory Management–Related Methods

Memory-Related Method	Description
+alloc	Allocate memory for new object and assign the object reference count of one.
−autorelease	Add receiver to autorelease pool.
−dealloc	Deallocate memory for an object with zero reference count.
−release	Decrease object’s
−retain	Increase object’s
−copy	See documentation.