iphone releas 后retatincount 替1

I created a simple program to test the retain/release methods in Objective-C memory management. As I understand of ObjC memory management, I expect that a object with retain count = 1 on which I callrelease?get the retain count decremented to zero and then released. But this test program show that after the first release I still get retain count = 1:

// TestClass.h#import <Cocoa/Cocoa.h>@interface TestClass : NSObject {}@end// TestClass.m#import "TestClass.h"@implementation TestClass@end// RetainRelease.m#import <Foundation/Foundation.h>#include "TestClass.h"void dumpRetain(id o);int main (int argc, const char * argv[]) {    TestClass *s = [[TestClass alloc] init];    dumpRetain(s);    [s release];    dumpRetain(s);}

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2010-08-13 17:42:45.489 RetainRelease[20933:a0f] NSString - retain count=12010-08-13 17:42:45.491 RetainRelease[20933:a0f] NSString - retain count=1

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答案：

?it's implemented as "when the object is released with a retainCount of 1, it's deallocated", because there's no need to ever decrement it to 0. It's an implementation optimization.

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