Objective-C：OC内部可变对象和不可变对象的深(复制)拷贝问题思考：

 1 //  Person.h
 2 //  测试
 3 //
 4 //  Created by ma c on 15/8/15.
 5 //  Copyright (c) 2015年 bjsxt. All rights reserved.
 6 //
 7 
 8 #import <Foundation/Foundation.h>
 9 
10 @interface Person : NSObject<NSCopying>
11 @property(nonatomic,copy)NSString *name;
12 -(id)initWithName:(NSString *)name;
13 -(void)print;
14 @end

 1 //  Person.m
 2 //  测试
 3 //
 4 //  Created by ma c on 15/8/15.
 5 //  Copyright (c) 2015年 bjsxt. All rights reserved.
 6 //
 7 
 8 #import "Person.h"
 9 
10 @implementation Person
11 -(id)initWithName:(NSString *)name
12 {
13     self = [super init];
14     if(self)
15     {
16         _name = [name mutableCopy]; //不可变深复制mutableCopy
17         //_name = [name copy];//不可变深复制copy
18     }
19     return self;
20 }
21 -(void)print
22 {
23     NSLog(@"%@",self);
24     NSLog(@"name:%@----%p",_name,_name);
25 }
26 -(id)copyWithZone:(NSZone *)zone
27 {
28     return [[Person alloc]initWithName:_name];
29 }
30 @end

 1 //  main.m
 2 //  测试
 3 //
 4 //  Created by ma c on 15/8/15.
 5 //  Copyright (c) 2015年 bjsxt. All rights reserved.
 6 //
 7 
 8 #import <Foundation/Foundation.h>
 9 #import "Person.h"
10 int main(int argc, const char * argv[])
11 {
12     @autoreleasepool
13     {
14         NSMutableString *name = [NSMutableString stringWithString:@"Jobs"];
15         Person *p1 = [[Person alloc]initWithName:name];
16         [p1 print];
17 
18        
19         Person *p2 = [p1 copy];
20         [p2 print];
21 
22 
23         [name appendString:@"Tom"];
24         Person *p3 = [[Person alloc]initWithName:name];
25         [p3 print];
26 
27 
28         Person *p4 = [p3 copy];
29         [p4 print];
30     }
31     return 0;
32 }

2015-08-15 20:35:58.163 测试[1713:126141] <Person: 0x100206c60>
2015-08-15 20:35:58.164 测试[1713:126141] name:Jobs----0x100206d30
2015-08-15 20:35:58.164 测试[1713:126141] <Person: 0x100300200>
2015-08-15 20:35:58.164 测试[1713:126141] name:Jobs----0x100300210
2015-08-15 20:35:58.165 测试[1713:126141] <Person: 0x1001002d0>
2015-08-15 20:35:58.165 测试[1713:126141] name:JobsTom----0x1001003e0
2015-08-15 20:35:58.165 测试[1713:126141] <Person: 0x100106980>
2015-08-15 20:35:58.165 测试[1713:126141] name:JobsTom----0x100100250
Program ended with exit code: 0


以上结果为mutableCopy深复制的结果：复制后一样的内容，可是各自所在的地址值是不同的，说明了系统为新创建的对象开辟了内存，这就是真正意义的深复制。

2015-08-15 20:41:16.156 测试[1724:127122] <Person: 0x100306c40>
2015-08-15 20:41:16.157 测试[1724:127122] name:Jobs----0x100306d10
2015-08-15 20:41:16.157 测试[1724:127122] <Person: 0x10010c8d0>
2015-08-15 20:41:16.157 测试[1724:127122] name:Jobs----0x100306d10
2015-08-15 20:41:16.157 测试[1724:127122] <Person: 0x1002009f0>
2015-08-15 20:41:16.158 测试[1724:127122] name:JobsTom----0x100200a00
2015-08-15 20:41:16.158 测试[1724:127122] <Person: 0x100200a60>
2015-08-15 20:41:16.158 测试[1724:127122] name:JobsTom----0x100200a00
Program ended with exit code: 0

以上结果为copy深复制结果，可以看出复制后一样的内容，可是它们的地址值是一样，说明了这并不是真正意义的深复制，而是假深复制，即最终结果是只是复制了指针。