ARC 迁移后属性和 ivars 发生变化

自从ARC（Automatic Reference Counting）在Objective-C中引入以来，它帮助开发人员简化了内存管理的工作。然而，在进行ARC迁移后，我们可能会注意到一些属性和实例变量（ivars）的变化。本文将探讨在ARC迁移后属性和ivars的变化，并提供一些示例代码来说明这些变化。

objective-c
// 非ARC环境下
@interface Person : NSObject {
    NSString *_name;
}
@property (nonatomic, retain) NSString *name;
@end
@implementation Person
@synthesize name = _name;
- (void)dealloc {
    [_name release];
    [super dealloc];
}
@end
// ARC环境下
@interface Person : NSObject
@property (nonatomic, strong) NSString *name;
@end

objective-c
// 非ARC环境下
@interface Person : NSObject {
    NSString *_name;
}
@end
@implementation Person
- (instancetype)initWithName:(NSString *)name {
    self = [super init];
    if (self) {
        _name = [name retain];
    }
    return self;
}
- (void)dealloc {
    [_name release];
    [super dealloc];
}
@end
// ARC环境下
@interface Person : NSObject
@property (nonatomic, strong) NSString *name;
@end
@implementation Person
- (instancetype)initWithName:(NSString *)name {
    self = [super init];
    if (self) {
        self.name = name;
    }
    return self;
}
@end