1 //  Person.h
 2 //  03-对象复制
 3 //
 4 //  Created by ma c on 15/8/14.
 5 //  Copyright (c) 2015年. All rights reserved.
 6 //
 7
 8 #import <Foundation/Foundation.h>
 9
10 @interface Person : NSObject<NSCopying>//实现NSCopying协议才能支持自定义对象的复制

11 @property(nonatomic,retain)NSMutableString *name;//(retain)浅拷贝,拷贝对象的引用,其实用的还是一个对象,相当于一个人给自己起了一个别名

12 @property(nonatomic,assign)NSInteger age;
13 -(id)initWithName:(NSMutableString*)name andAge:(NSInteger)age;
14 -(void)show;
15 @end

 1 //  Person.m
 2 //  03-对象复制
 3 //
 4 //  Created by ma c on 15/8/14.
 5 //  Copyright (c) 2015年. All rights reserved.
 6 //
 7
 8 #import "Person.h"
 9
10 @implementation Person
11 -(id)initWithName:(NSMutableString*)name andAge:(NSInteger)age
12 {
13     self = [super init];
14     if(self)
15     {
16         _name = [name retain];//强引用,获得对象所有权
17         _age = age;
18     }
19     return self;
20 }
21 -(void)show
22 {
23     NSLog(@"name:%@,age:%lu",_name,_age);
24 }
25 -(void)dealloc
26 {
27     [_name release];
28     [super dealloc];
29 }
30 -(id)copyWithZone:(NSZone *)zone
31 {
32     return [[Person alloc]initWithName:_name andAge:_age];
33 }
34 @end

 1 //  main.m
 2 //  03-对象复制
 3 //
 4 //  Created by ma c on 15/8/14.
 5 //  Copyright (c) 2015年. All rights reserved.
 6 //
 7
 8 #import <Foundation/Foundation.h>
 9 #import "Person.h"
10 int main(int argc, const char * argv[]) {
11     @autoreleasepool {
12         // 测试Person类
13         NSMutableString *name = [NSMutableString stringWithString:@"Tom"];
14
15         Person *p1 = [[Person alloc]initWithName:name andAge:20];
16         [p1 show];
17
18         [name appendString:@"Jerry"];
19
20         Person *p2 = [[Person alloc]initWithName:name andAge:21];
21         [p2 show];
22
23         [p1 show];
24
25         //对象复制,自定义对象必须要实现NSCopying协议才能支持对象复制
26         Person *p3 = [p1 copy];
27         [p3 show];
28
29         [p1.name appendString:@"123"];//因为retain,p1和p2指向同一对象,一改都改
30         [p3 show];
31
32         NSMutableString *name2 = [NSMutableString stringWithString:@"Jobs"];
33         [p1 setName:name2];//p1和p3指向的是不同的对象,互不影响
34         [p3 show];
35
36         [p1 release];
37         [p2 release];
38         [p3 release];
39     }
40     return 0;
41 }

2015-08-14 16:40:59.293 03-对象复制[1460:96685] name:Tom,age:20
2015-08-14 16:40:59.294 03-对象复制[1460:96685] name:TomJerry,age:21
2015-08-14 16:40:59.294 03-对象复制[1460:96685] name:TomJerry,age:20
2015-08-14 16:40:59.295 03-对象复制[1460:96685] name:TomJerry,age:20
2015-08-14 16:40:59.295 03-对象复制[1460:96685] name:TomJerry123,age:20
2015-08-14 16:40:59.295 03-对象复制[1460:96685] name:TomJerry123,age:20
Program ended with exit code: 0