手动内存管理

#import "Person.h"
#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{
    @autoreleasepool {

        Person * p = [Person new];
        NSUInteger count = [p retainCount];
        NSLog(@"count = %lu", count);

        Person * p2 = [p retain];

        NSLog(@"p2.retainCount = %lu", [p retainCount]);

        [p release];
        [p release];

        NSLog(@"p Soon to be released , Because retainCount = %lu",
            [p retainCount]);
    }
    return 0;
}