Shallow copy, deep copy---ios

#import <Foundation/Foundation.h> @interface father:nsobject <NSCopying,NSMutableCopying> @property ( nonatomic,copy) NSString *name; @property (nonatomic,retain) nsnumber *age;-(ID) initwithname: (NSString *) name WithAge :(NSNumber *) age; @end

#import "Father.h" #import "Child.h" @implementation father-(ID) initwithname: (NSString *) name Withage: (NSNumber *) age{    self=[super init];    if (self!=nil) {        _name=name;        _age=age;    }    return self;} Shallow copy-(ID) Copywithzone: (Nszone *) zone{    Father *father=[[[self class] allocwithzone:zone] init];    Father.name=_name;    Father.age=_age;    return father;} Deep copy-(ID) Mutablecopywithzone: (Nszone *) zone{    Father *father=[[[self class] allocwithzone:zone] init];    Father.name=[_name Mutablecopy];    Father.age=[_age copy];    return self;}

 NSLog (@ "-------the custom object shallow copy---------");        Shallow copy Learning Father *father=[[father alloc] initwithname:@ "Caitou" Withage:[nsnumber numberwithint:23];        Father *father2=[father Copy];        NSLog (@ "Object address:%p", father);        NSLog (@ "Object address:%p", father2);        NSLog (@ "object property Address Name:%p", [father name]);        NSLog (@ "object property Address Name:%p", [father2 name]);        NSLog (@ "Object attribute address age:%p", [Father Age]);                 NSLog (@ "Object attribute address age:%p", [father2 age]);        NSLog (@ "--------the custom object deep copy---------");        Deep copy Father *father4=[[father alloc] initwithname:@ "Caitou" Withage:[nsnumber numberwithint:25];        Father *father3=[father4 Mutablecopy];        NSLog (@ "Object address:%p", father4);        NSLog (@ "Object address:%p", Father3);        NSLog (@ "object property Address Name:%p", [father4 name]);        NSLog (@ "object property Address Name:%p", [father3 name]);        NSLog (@ "Object attribute address age:%p", [father4 age]);                NSLog (@ "Object attribute address age:%p", [Father3 age]);        NSLog (@ "-------shallow copy---------"); Nsarray *array1=[[nsarray Alloc] Initwithobjects:@ "SDF", nil];        Nsarray *array2=[array1 Copy];        NSLog (@ "%p", array1);                NSLog (@ "%p", array2);        NSLog (@ "-------deep copy---------");        Nsmutablearray *mutablearray=[nsmutablearray arraywithobject:@ "SDFDF"];        Nsmutablearray *mutablearray2=[mutablearray Mutablecopy];        NSLog (@ "%p", Mutablearray);        NSLog (@ "%p", mutableArray2); Summary: When copying an immutable object, it is quite retain, that is, the reference count plus one, other cases copy,mutablecopy will allocate space to copy content