关于OC对象拷贝的问题

先来打一下实例：

创建一个Person类：

Person.h:

#import <Foundation/Foundation.h>

@interface Person : NSObject<NSCopying>

@property(nonatomic,assign) int age;
@property(nonatomic,retain) NSString *name;

@end

#import "Person.h"

@implementation Person

- (id)init
{
    self = [super init];
    if (self) {
        self.name = @"xiaoming";
        self.age = 22;
    }
    return self;
}
//构造拷贝函数,虽然说内存管理的原则是谁retain谁release，但是对copy来说比较特殊，是放在外面release的
-(id)copyWithZone:(NSZone *)zone
{
    Person *p = [[Person allocWithZone:zone] init];
    p.name = self.name;  //浅拷贝，只是拷贝了地址
    p.age = self.age;   
    
    //深拷贝
    //p.name = [self.name copy];//内容拷贝一份
    return p;
}

- (void)dealloc
{
    [_name release];
    [super dealloc];
}

@end

#import <Foundation/Foundation.h>
#import "Person.h"
int main(int argc, const char * argv[])
{

    @autoreleasepool {
        
        Person *p = [[Person alloc] init];
        p.age = 11;
        NSMutableString *str = [NSMutableString stringWithFormat:@"xiaohua"];
        p.name = str;
        NSLog(@"person age = %d name = %@",p.age,p.name);
        
        Person *p1 = [p copy];
        [str appendString:@"1"]; //在原来的基础上加1
        NSLog(@"person age = %d name = %@",p.age,p.name); //验证原来的对象是否改变
        NSLog(@"p1 age = %d name = %@",p1.age,p1.name);  //打印当然的拷贝对象，这个要看前面的拷贝实现的函数是深拷贝还是浅拷贝
        
        [p1 release];
        [p release];
    }
    return 0;
}

2013-08-05 11:35:39.688 对象拷贝[862:303] person age = 11 name = xiaohua

2013-08-05 11:35:39.690 对象拷贝[862:303] person age = 11 name = xiaohua1

2013-08-05 11:35:39.691 对象拷贝[862:303] p1 age = 11 name = xiaohua1

2013-08-05 11:39:26.579 对象拷贝[892:303] person age = 11 name = xiaohua

2013-08-05 11:39:26.581 对象拷贝[892:303] person age = 11 name = xiaohua1

2013-08-05 11:39:26.582 对象拷贝[892:303] p1 age = 11 name = xiaohua