Summary

These are the key points of Objective-C’s reference counting memory management system:

• An object’s retain count keeps track of the number of other objects that are using the object. The retain count is frequently expressed as the number of owners an object has.

• Objects are created with a retain count of one.

• Sending an object a retain message increases its retain count by one.

• Sending an object a release message reduces its retain count by one.

• An autorelease message has no immediate effect, but it arranges to send a release message to its receiver at some future time.

• When an object’s retain count reaches zero, the object is deallocated.