Question

I’m still learning about Objective-C memory management. I’m trying to implement several simple classes in an example program that I’m building.

As an example, say I have the following class definition:

 #import <UIKit/UIKit.h>

 @interface customViewController : UIViewController 
 {
    customObject *myCustomObject;
 }

 @property (retain) customObject *myCustomObject;

 - (void)replaceCustomObject:(customObject *)newObject;

 @end

For the property, I use the standard synthesize keyword…

@synthesize myCustomObject;

Then please assume that in the instance of customViewController the myCustomObject is already set with a valid value and is in use. Then the method replaceCustomObject is defined as:

 - (void)replaceCustomObject:(customObject *)newObject
 {
     //Does this cause a memory leak because I just assign over
     //the existing property? 
     self.myCustomObject = newObject;
 }

As the comment asks, does this leak memory? Or is this the valid way to replace a previous object with a new object?

Thank you,
Frank

Answer 1

That’s perfectly valid, and does not leak memory. The synthesized accessors manage retain counts correctly.

(As an aside, you don’t need that replaceCustomObject: method; since your property is readwrite by default, you have an auto-generated setCustomObject: method that clients of your class can use, and which follows the normal Cocoa naming conventions.)