Objective-C个人学习系列（七） 内存管理与深 浅复制
#import <Foundation/Foundation.h>
#import "Person.h"
int main(int argc, const char * argv[])
{
@autoreleasepool {
//内存管理规则：只要有alloc、retain、new、copy、mutablecopy的地方，都要有对应的release。
//[Object new] => [[Object alloc] init]
NSString * string = [[NSString alloc]initWithFormat: @"123"];
NSLog(@"string retainCount=%ld",[string retainCount]);
[string retain];
NSLog(@"string retainCount=%ld",[string retainCount]);
[string release];
NSLog(@"string retainCount=%ld",[string retainCount]);
NSString * string2 = [string copy];
//NSString: copy => [string retain] NSString的copy 只是将计数器＋1
NSLog(@"string2 retainCount=%ld",[string2 retainCount]);
NSLog(@"string retainCount=%ld",[string retainCount]);
[string2 release];
[string release];
NSLog(@"string retainCount=%ld",[string retainCount]);
//***********************copy 和 mutableCopy****************************
//copy : 不可变复制，需要实现协议<NSCopying>
NSString * _str = [[NSString alloc] initWithFormat:@"AAA"];
Person * person = [[Person alloc] initWithName:_str sex:18];
//
Person *person2 = [person copy];
NSLog(@"person->_name=%@",person->_name); //person->_name=AAA
NSLog(@"person2->_name=%@",person2->_name); //person2->_name=AAA
[person setName:@"BBB"];
NSLog(@"不可变复制：");
NSLog(@"person->_name=%@",person->_name); //person->_name=BBB
NSLog(@"person2->_name=%@",person2->_name); //person2->_name=AAA
//mutalbeCopy:可变复制，需要实现<NSMutalbeCopying>
Person *person3 = [person mutableCopy];
[person setName:@"CCC"];
NSLog(@"可变复制：");
NSLog(@"person->_name=%@",person->_name); //person->_name=CCC
NSLog(@"person3->_name=%@",person3->_name); //person2->_name=BBB
[_str release];
[person release];
[person2 release];
[person3 release];
//浅复制：在复制操作时，对于被复制的对象的每一层复制都是指针复制。
//深复制：在复制操作时，对于被复制的对象至少有一层复制是对象复制。
//*************************可变&不可变字符串的不可变复制与可变复制*******************
//1、不可变字符串
NSString * str = [[NSString alloc] initWithFormat:@"abc"];
//1)不可变字符串的不可变复制(地址不变，只是引用计数＋1)
NSLog(@"不可变字符串的不可变复制");
NSString *str2 = [str copy];
NSLog(@"NSString &str = %p",str); //str = 0x100105b00
NSLog(@"NSString &str2 = %p",str2); //str2 = 0x100105b00
//2)不可变字符串的可变复制（地址改变，逻辑上可认为深度复制）
NSLog(@"不可变字符串的可变复制");
NSMutableString *str3 = [str mutableCopy];
NSLog(@"NSMutableString &str = %p",str); //str = 0x100105b00
NSLog(@"NSMutableString &str3 = %p",str3); //str3 = 0x100108a50
NSLog(@"str = %@",str); //str = abc
NSLog(@"str3 = %@",str3); //str3 = abc
[str3 appendString:@"123"];
NSLog(@"str = %@",str); //str = abc
NSLog(@"str3 = %@",str3); //str3 = abc123
//2、可变字符串
NSMutableString *mStr = [[NSMutableStringalloc]initWithFormat:@"abcde"];
//1)可变字符串的不可变复制(地址改变，复制字符串对象，并且复制字符串内容，深度copy)
NSLog(@"可变字符串的不可变复制");
NSMutableString *mStr2 = [mStr copy];
NSLog(@"NSMutableString &mStr = %p",mStr); // &mStr = 0x100206f80
NSLog(@"NSMutableString &mStr2 = %p",mStr2); //&mStr2 = 0x100205fd0
NSLog(@"mStr = %@",mStr); //mStr = abcde
NSLog(@"mStr2 = %@",mStr2); //mStr2 = abcde
[mStr appendString:@"qqq"];
NSLog(@"mStr = %@",mStr); //mStr = abcdeqqq
NSLog(@"mStr2 = %@",mStr2); //mStr2 = abcde
//2)可变字符串的可变复制（地址改变，复制字符串对象，同时复制字符串内容，深度copy）
NSLog(@"可变字符串的可变复制");
NSMutableString *mStr3 = [mStr mutableCopy];
NSLog(@"NSMutableString &mStr = %p",mStr); // &mStr = 0x100206b40
NSLog(@"NSMutableString &mStr3 = %p",mStr3); // &mStr3 = 0x100206de0
NSLog(@"mStr = %@",mStr); //mStr = abcde
NSLog(@"mStr3 = %@",mStr3); //mStr3 = abcde
[mStr appendString:@"888"];
NSLog(@"mStr = %@",mStr); //mStr = abcde888
NSLog(@"mStr3 = %@",mStr3); //mStr3 = abcde
[str release];
[str2 release];
[str3 release];
[mStr release];
[mStr2 release];
[mStr3 release];
//**********************可变&不可变字符串数组的不可变复制与可变复制************************
NSMutableString* s1 = [[NSMutableStringalloc]initWithFormat:@"A"];
NSMutableString* s2 = [[NSMutableStringalloc]initWithFormat:@"B"];
NSMutableString* s3 = [[NSMutableStringalloc]initWithFormat:@"C"];
//1、不可变字符串数组
NSArray *array = [[NSArray alloc]initWithObjects:s1,s2,s3, nil];
//1）不可变字符数组的不可变复制（地址不变，只是引用计数＋1，同NSString）
NSLog(@"不可变字符串数组的不可变复制");
NSArray *array2 = [array copy];
NSLog(@"&array = %p",array); //array = 0x100203da0
NSLog(@"&array2 = %p",array2); //array2 = 0x100203da0
//2）可变复制（地址改变，复制字符串数组对象，但字符数组中字符串内容不改变，深度copy）
NSLog(@"不可变字符串数组的可变复制");
NSArray *array3 = [array mutableCopy];
NSLog(@"&array = %p",array); //array = 0x100203da0
NSLog(@"&array3 = %p",array3); //array3 = 0x100203b20
NSLog(@"array[0]->%@",array[0]); //mArray->A
NSLog(@"array3[0]->%@",array3[0]); //mArray3->A
//改变数组中字符串的值
[array[0] appendString:@"123"];
NSLog(@"array[0]->%@",array[0]); //array[0]->A123
NSLog(@"array3[0]->%@",array3[0]); //array3[0]->A123
//2、可变字符串数组
NSMutableArray *mArray = [[NSMutableArray alloc]initWithObjects:s1,s2,s3, nil];
//1）可变字符串数组的不可变复制（地址改变，复制字符对象，数组中字符对象内容不变，深度copy）
NSLog(@"可变字符串数组的不可变复制");
NSMutableArray *mArray2 = [mArray copy];
NSLog(@"&mArray = %p",mArray); //mArray = 0x100100310
NSLog(@"&mArray2 = %p",mArray2); //mArray2 = 0x10010c200
NSLog(@"mArray->%@",mArray[0]); //mArray->A
NSLog(@"mArray2->%@",mArray2[0]); //mArray2->A
//改变数组中字符串的值
[mArray[0] appendString:@"333"];
NSLog(@"mArray->%@",mArray[0]); //mArray->A333
NSLog(@"mArray2->%@",mArray2[0]); //mArray2->A333
//2）可变字符串数组的可变复制（地址改变，复制数组对象，但数组中字符对象内容不变，深度copy）
NSLog(@"可变字符串数组的可变复制");
NSMutableArray *mArray3 = [mArray copy];
NSLog(@"&mArray = %p",mArray); //mArray = 0x100208440
NSLog(@"&mArray3 = %p",mArray3); //mArray3 = 0x100208f30
NSLog(@"mArray->%@",mArray[0]); //mArray->A333
NSLog(@"mArray3->%@",mArray3[0]); //mArray3->A333
//改变数组中字符串的值
[mArray[0] appendString:@"444"];
NSLog(@"mArray->%@",mArray[0]); //mArray->A333444
NSLog(@"mArray3->%@",mArray3[0]); //mArray2->A333444
[s1 release];
[s2 release];
[s3 release];
[array release];
[array2 release];
[array3 release];
[mArray release];
[mArray2 release];
[mArray3 release];
}
return 0;
}
#import "Person.h"
@implementation Person
-(id)initWithName:(NSString *)name sex:(unsigned char)sex{
self = [super init];
if (self != nil ) {
if (name==NULL) {
return NULL;
}
_name = [name retain];
_sex = sex;
}
returnself;
}
-(void)setName:(NSString *)name{
[name retain];
[_name release];
_name = name;
}
-(id)copyWithZone:(NSZone *)zone{
Person *person = [[Person allocWithZone:zone] initWithName:_name sex:_sex];
return person;
}
- (id)mutableCopyWithZone:(NSZone *)zone{
Person *person = [[Person allocWithZone:zone] initWithName:_name sex:_sex];
return person;
}
-(void)dealloc{
[_name release];
_name = nil;
[super dealloc];
}
@end
#import <Foundation/Foundation.h>
@interface Person : NSObject<NSCopying,NSMutableCopying>{
@public
NSString* _name;
unsignedchar _sex;
}
-(id)initWithName:(NSString*)name sex:(unsigned char)sex;
-(void)setName:(NSString*)name;
- (id)copyWithZone:(NSZone *)zone;
- (id)mutableCopyWithZone:(NSZone *)zone;
@end
#import "Person.h"
@implementation Person
-(id)initWithName:(NSString *)name sex:(unsigned char)sex{
self = [super init];
if (self != nil ) {
if (name==NULL) {
return NULL;
}
_name = [name retain];
_sex = sex;
}
returnself;
}
-(void)setName:(NSString *)name{
[name retain];
[_name release];
_name = name;
}
-(id)copyWithZone:(NSZone *)zone{
Person *person = [[Person allocWithZone:zone] initWithName:_name sex:_sex];
return person;
}
- (id)mutableCopyWithZone:(NSZone *)zone{
Person *person = [[Person allocWithZone:zone] initWithName:_name sex:_sex];
return person;
}
-(void)dealloc{
[_name release];
_name = nil;
[super dealloc];
}
@end