Objective-C基础学习之copy与内存管理
2017-10-27 本文已影响8人
WenJim
1.copy与内存管理
- 浅拷贝
- 原对象引用计数器+1
- 必须对原对象进行释放
char *cstr = "this is a c string";
NSString *str1 = [[NSString alloc] initWithUTF8String:cstr];
NSLog(@"str = %lu", [str1 retainCount]);
NSString *str2 = [str1 copy];
NSLog(@"str = %lu", [str1 retainCount]);
[str2 release];必须做一次release
- 深拷贝
- 必须释放新对象
char *cstr = "this is a c string";
NSString *str1 = [[NSString alloc] initWithUTF8String:cstr];
NSLog(@"str = %lu", [str1 retainCount]);
NSMutableString *str2 = [str1 mutableCopy];
NSLog(@"str = %lu", [str1 retainCount]);
[str2 release]; // 必须做一次release