3)、深复制Demo
Dog.h文件一样
Dog.m文件有点变化
#import <Foundation/Foundation.h> #import "Dog.h" @implementation Dog @synthesize name; @synthesize age; -(id)copyWithZone:(NSZone *)zone { Dog *dog = [[[self class] allocWithZone:zone] init]; // dog.name = self.name; dog.name = [self.name mutableCopy]; dog.age = self.age; return dog; } @end
main.m文件一样
Dog *dog1 = [Dog new]; dog1.name = [NSMutableString stringWithString:@"chen"]; dog1.age = 1; NSLog(@"dog1.name is %@ and age is %d", dog1.name, dog1.age); //深复制 Dog *dog2 = [dog1 copy]; // dog2.name = [NSMutableString stringWithString:@"li"]; [dog2.name replaceCharactersInRange:NSMakeRange(1, 2) withString:@"hel"]; dog2.age = 20; NSLog(@"dog2.name is %@ and age is %d", dog2.name, dog2.age); NSLog(@"dog1.name is %@ and age is %d", dog1.name, dog1.age);
4)、运行结果
2018-07-15 19:13:08.751335+0800 cyTest[27529:9427019] dog1.name is chen and age is 1 2018-07-15 19:13:08.751686+0800 cyTest[27529:9427019] dog2.name is cheln and age is 20 2018-07-15 19:13:08.751885+0800 cyTest[27529:9427019] dog1.name is chen and age is 1
4、setter方法的复制选项
我们setter方法复制选项的时候，如果加了copy属性，比如setName方法
-(void)setName : (NSMutableStrinfg *)name { self.name = [name copy]; }
#import <Foundation/Foundation.h> #import "Dog.h" @implementation Dog @synthesize name; @synthesize age; @end
所以当对象设置了name属性的话，就不能再改变了，如下demo
Dog.h
#import <Foundation/Foundation.h> #ifndef Dog_h #define Dog_h @interface Dog : NSObject @property (nonatomic, copy) NSMutableString *name; @property (nonatomic, assign) int age; @end #endif /* Dog_h */
Dog.m
#import <Foundation/Foundation.h> #import "Dog.h" @implementation Dog @synthesize name; @synthesize age; @end
main.m
Dog *dog1 = [Dog new]; dog1.name = [NSMutableString stringWithString:@"chen"]; dog1.age = 1; [dog1.name appendString:@"hello"];
运行结果
2018-07-15 19:22:17.736557+0800 cyTest[27853:9436238] -[NSTaggedPointerString appendString:]: unrecognized selector sent to instance 0xa0000006e6568634 2018-07-15 19:22:17.739655+0800 cyTest[27853:9436238] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSTaggedPointerString appendString:]: unrecognized selector sent to instance 0xa0000006e6568634' *** First throw call stack: ( 0 CoreFoundation 0x0000000104fd61e6 __exceptionPreprocess + 294 1 libobjc.A.dylib 0x000000010466b031 objc_exception_throw + 48 2 CoreFoundation 0x0000000105057784 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132 3 CoreFoundation 0x0000000104f58898 ___forwarding___ + 1432 4 CoreFoundation 0x0000000104f58278 _CF_forwarding_prep_0 + 120 5 cyTest 0x0000000103d60438 main + 600 6 libdyld.dylib 0x0000000108a2f955 start + 1 ) libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)
