寫一個 setter 方法用於完成 @property (nonatomic, retain) NSString *name
寫一個 setter 方法用於完成 @property (nonatomic, copy) NSString *name
答：
// retain
- (void)setName:(NSString *)str {
[str retain];
[_name release];
_name = str;
}
// copy
- (void)setName:(NSString *)str {
id t = [str copy];
[_name release];
_name = t;
}