Objective-C 淺拷貝、深拷貝、完全拷貝

在Objective-C中，對(duì)對(duì)象的拷貝可分為淺拷貝、深拷貝和完全拷貝。

copy、mutableCopy和容器拷貝總結(jié)：
  1. copy對(duì)于可變對(duì)象為深拷貝，對(duì)于不可變對(duì)象為淺拷貝。
  2. mutableCopy始終是深拷貝。
  3. 對(duì)容器進(jìn)行拷貝，容器內(nèi)元素始終為淺拷貝。
淺拷貝、深拷貝和完全拷貝總結(jié)：
  1. 淺拷貝(shallow copy)：僅僅對(duì)內(nèi)存地址進(jìn)行了拷貝，并沒有對(duì)源對(duì)象進(jìn)行拷貝；對(duì)于被復(fù)制對(duì)象的每一層都是指針復(fù)制。
  2. 深拷貝(one-level-deep copy)：不僅對(duì)內(nèi)存地址進(jìn)行拷貝，而且對(duì)源對(duì)象進(jìn)行拷貝；對(duì)于被復(fù)制對(duì)象，至少有一層是深復(fù)制。
  3. 完全深拷貝(real-deep copy)：在拷貝的時(shí)候，對(duì)于被拷貝對(duì)象的每一層都進(jìn)行了拷貝。
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eg1. 不可變?cè)瓟?shù)據(jù)執(zhí)行 copy，mutableCopy操作：
image.png

eg2. 可變?cè)瓟?shù)據(jù)執(zhí)行 copy，mutableCopy操作：
image.png

eg3. 自定義模型(YYModel)數(shù)據(jù)執(zhí)行 copy，mutableCopy操作：
image.png

eg4. 自定義模型(NSCoding,NSCopying)數(shù)據(jù)歸檔解檔、initWithArray:copyItems:操作：
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eg5. 自定義模型嵌套自定義模型(NSCoding,NSCopying)數(shù)據(jù)歸檔解檔、initWithArray:copyItems:操作：

NSMutableArray *array = [[NSMutableArray alloc] init];
Person *person = [[Person alloc] init];
person.name = [NSString stringWithFormat:@"張三"];
person.age = 18;
[array addObject:person];

// 不完全深拷貝
NSArray *arrCopy = [array copy];
NSMutableArray *arrMCopy = [array mutableCopy];
Person *person1 = [array firstObject];
Person *perCopy = arrCopy.firstObject;
Person *perMCopy =arrMCopy.firstObject;
perCopy.name = @"李四";
perMCopy.name = @"王五";

NSLog(@"不完全深拷貝");
NSLog(@"array= %p, person= %@, name= %@", array, person1, person1.name);
NSLog(@"arrCopy= %p, person= %@, name= %@", arrCopy, perCopy, perCopy.name);
NSLog(@"arrMCopy= %p, person= %@, name= %@", arrMCopy, perMCopy, perMCopy.name);

//方式1 要在集合對(duì)象中實(shí)現(xiàn)NSCoding協(xié)議
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:array];
NSArray *array2 = [NSKeyedUnarchiver unarchiveTopLevelObjectWithData:data error:nil];

    
//方式2 要在集合對(duì)象中實(shí)現(xiàn)NSCopying協(xié)議
NSMutableArray *array3 = [[NSMutableArray alloc] initWithArray:array copyItems:YES];

Person *person2 = [array2 firstObject];
Person *person3 = [array3 firstObject];
person2.name = @"李四一";
person3.name = @"王五一";
NSLog(@"完全深拷貝");
NSLog(@"array= %p, person= %@, name= %@", array, person1, person1.name);
NSLog(@"array2= %p, person= %@, name= %@", array2, person2, person2.name);
NSLog(@"array3= %p, person= %@, name= %@", array3, person3, person3.name);

/*
2022-10-12 14:41:37.732284+0800 OC深淺拷貝[52457:290164] 不完全深拷貝
2022-10-12 14:41:37.732661+0800 OC深淺拷貝[52457:290164] array= 0x10120e030, person= <Person: 0x10073c1e0>, name= 王五
2022-10-12 14:41:37.732744+0800 OC深淺拷貝[52457:290164] arrCopy= 0x10073a360, person= <Person: 0x10073c1e0>, name= 王五
2022-10-12 14:41:37.732798+0800 OC深淺拷貝[52457:290164] arrMCopy= 0x10073c1b0, person= <Person: 0x10073c1e0>, name= 王五
2022-10-12 14:41:37.733398+0800 OC深淺拷貝[52457:290164] 完全深拷貝
2022-10-12 14:41:37.733525+0800 OC深淺拷貝[52457:290164] array= 0x10120e030, person= <Person: 0x10073c1e0>, name= 王五
2022-10-12 14:41:37.733596+0800 OC深淺拷貝[52457:290164] array2= 0x10140b8e0, person= <Person: 0x10140b560>, name= 李四一
2022-10-12 14:41:37.733657+0800 OC深淺拷貝[52457:290164] array3= 0x10140a280, person= <Person: 0x10140a330>, name= 王五一
**/

@interface Person : NSObject <NSCoding,NSCopying, NSMutableCopying>

@property NSString *name;
@property NSInteger  age;

@end

@interface Worker : Person <NSCoding,NSCopying>

@property NSString *salary;
@property Person *leader;

@end

@implementation Person
 
- (id)copyWithZone:(nullable NSZone *)zone{
 
    Person *copy = [[[self class] allocWithZone:zone] init];
    copy.name = [self.name copy];
    copy.name = [self.name mutableCopy];// copy，mutableCopy二選一
    copy.age = self.age;
    return copy;
}

- (id)mutableCopyWithZone:(NSZone *)zone {
    
   Person *copy = [[[self class] allocWithZone:zone] init];
    copy.name = [self.name copy];
   copy.name = [self.name mutableCopy];// copy，mutableCopy二選一
   copy.age = self.age;
   return copy;
}

- (void)encodeWithCoder:(NSCoder *)aCoder{

    [aCoder encodeObject:self.name forKey:@"name"];
    [aCoder encodeInteger:self.age forKey:@"age"];
}

- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder{

    _name = [aDecoder decodeObjectForKey:@"name"];
    _age = [aDecoder decodeIntegerForKey:@"age"];
    return self;
}

@end


@implementation Worker
 
- (id)copyWithZone:(nullable NSZone *)zone{
 
    Worker *copy = [[[self class] allocWithZone:zone] init];
    copy.salary = [self.salary copy];
    copy.salary = [self.salary mutableCopy];// copy，mutableCopy二選一
    copy.leader = [self.leader copy];
    copy.leader = [self.leader mutableCopy];// 注意要實(shí)現(xiàn)NSMutableCopying; copy，mutableCopy二選一
    return copy;
}
 
- (void)encodeWithCoder:(NSCoder *)aCoder{

    [aCoder encodeObject:self.salary forKey:@"salary"];
    [aCoder encodeObject:self.leader forKey:@"leader"];
}

- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder{

    _salary = [aDecoder decodeObjectForKey:@"salary"];
    _leader = [aDecoder decodeObjectForKey:@"leader"];
    return self;
}

NSMutableArray *array = [[NSMutableArray alloc] init];
Worker *worker = [[Worker alloc] init];
worker.name = [NSString stringWithFormat:@"張三"];
worker.age = 25;
worker.salary = @"200";
Person *leader = [[Person alloc] init];
leader.name = [NSString stringWithFormat:@"領(lǐng)導(dǎo)"];
leader.age = 30;
worker.leader = leader;

[array addObject:worker];

// 不完全深拷貝
NSArray *arrCopy = [array copy];
NSMutableArray *arrMCopy = [array mutableCopy];
Worker *worker1 = [array firstObject];
Worker *wkrCopy = arrCopy.firstObject;
Worker *wkrMCopy =arrMCopy.firstObject;
wkrCopy.name = @"李四";
wkrMCopy.name = @"王五";
wkrCopy.leader.name = @"李四的領(lǐng)導(dǎo)";
wkrMCopy.leader.name = @"王五的領(lǐng)導(dǎo)";

NSLog(@"不完全深拷貝");
NSLog(@"array= %p, person= %@, name= %@, leader= %p, %@, name= %@", array, worker1, worker1.name, worker1.leader, worker1.leader, worker1.leader.name);
NSLog(@"arrCopy= %p, person= %@, name= %@, leader= %p, %@, name= %@", arrCopy, wkrCopy, wkrCopy.name, wkrCopy.leader, wkrCopy.leader, wkrCopy.leader.name);
NSLog(@"arrMCopy= %p, person= %@, name= %@, leader= %p, %@, name= %@", arrMCopy, wkrMCopy, wkrMCopy.name, wkrMCopy.leader, wkrMCopy.leader, wkrMCopy.leader.name);

//方式1 要在集合對(duì)象中實(shí)現(xiàn)NSCoding協(xié)議
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:array];
NSArray *array2 = [NSKeyedUnarchiver unarchiveTopLevelObjectWithData:data error:nil];

    
//方式2 要在集合對(duì)象中實(shí)現(xiàn)NSCopying協(xié)議
NSMutableArray *array3 = [[NSMutableArray alloc] initWithArray:array copyItems:YES];

Worker *worker2 = [array2 firstObject];
Worker *worker3 = [array3 firstObject];
worker2.name = @"李四一";
worker3.name = @"王五一";
worker2.leader.name = @"李四一的領(lǐng)導(dǎo)";
worker3.leader.name = @"王五一的領(lǐng)導(dǎo)";
NSLog(@"完全深拷貝");
NSLog(@"array= %p, person= %@, name= %@, leader= %p, %@, name= %@", array, worker1, worker1.name, worker1.leader, worker1.leader, worker1.leader.name);
NSLog(@"array2= %p, person= %@, name= %@, leader= %p, %@, name= %@", array2, worker2, worker2.name, worker2.leader, worker2.leader, worker2.leader.name);
NSLog(@"array3= %p, person= %@, name= %@, leader= %p, %@, name= %@", array3, worker3, worker3.name, worker3.leader, worker3.leader, worker3.leader.name);

/*
2022-10-12 14:41:37.733737+0800 OC深淺拷貝[52457:290164] 不完全深拷貝
2022-10-12 14:41:37.733809+0800 OC深淺拷貝[52457:290164] array= 0x10140a280, person= <Worker: 0x10140a630>, name= 王五, leader= 0x10140ac80, <Person: 0x10140ac80>, name= 王五的領(lǐng)導(dǎo)
2022-10-12 14:41:37.733867+0800 OC深淺拷貝[52457:290164] arrCopy= 0x10140a6e0, person= <Worker: 0x10140a630>, name= 王五, leader= 0x10140ac80, <Person: 0x10140ac80>, name= 王五的領(lǐng)導(dǎo)
2022-10-12 14:41:37.735200+0800 OC深淺拷貝[52457:290164] arrMCopy= 0x10140b070, person= <Worker: 0x10140a630>, name= 王五, leader= 0x10140ac80, <Person: 0x10140ac80>, name= 王五的領(lǐng)導(dǎo)
2022-10-12 14:41:37.735675+0800 OC深淺拷貝[52457:290164] 完全深拷貝
2022-10-12 14:41:37.735798+0800 OC深淺拷貝[52457:290164] array= 0x10140a280, person= <Worker: 0x10140a630>, name= 王五, leader= 0x10140ac80, <Person: 0x10140ac80>, name= 王五的領(lǐng)導(dǎo)
2022-10-12 14:41:37.735899+0800 OC深淺拷貝[52457:290164] array2= 0x101039ad0, person= <Worker: 0x10103a650>, name= 李四一, leader= 0x101038fe0, <Person: 0x101038fe0>, name= 李四一的領(lǐng)導(dǎo)
2022-10-12 14:41:37.735977+0800 OC深淺拷貝[52457:290164] array3= 0x101608210, person= <Worker: 0x101039b80>, name= 王五一, leader= 0x101605d60, <Person: 0x101605d60>, name= 王五一的領(lǐng)導(dǎo)
**/
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