佚名通过本文主要向大家介绍了getter和setter方法,idea getter setter,setter getter,vue getter setter,java setter getter等相关知识,希望对您有所帮助,也希望大家支持linkedu.com www.linkedu.com
问题： (swift)iOS中getter/setter的问题
描述:
解决方案1:
描述:
Class - Person
@interface Person : NSObject
@property (nonatomic, copy) NSString *lastName;
@end
@implementation Person
@synthesize lastName = _lastName;
- (instancetype)init {
self = [super init];
if (self) {
_lastName = @"abc";
}
return self;
}
- (NSString *)lastName {
return _lastName;
}
- (void)setLastName:(NSString *)lastName {
_lastName = lastName;
}
@end
Class - SmithPerson
@interface SmithPerson : Person
@end
@implementation SmithPerson
- (instancetype)init {
self = [super init];
if (self) {
self.lastName = @"aaa";
}
return self;
}
@end以上在子类SmithPerson中没有重写lastName的getter/setter方法，我可以在init中通过self.lastName重新赋值，但是如果我在子类重写了getter/setter，那怎么重新赋值呢？self.lastName会调用子类的setter方法，setter中如果这样赋值就死循环了
- (void)setLastName:(NSString *)lastName {
self.lastName = lastName;
}另外：如果将Person和SmithPerson的init方法改成下面这样，同时子类重写父类lastName的getter/setter：
Person
- (instancetype)init {
self = [super init];
if (self) {
**self.lastName = @"abc";**
}
return self;
}
SmithPerson
- (instancetype)init {
self = [super init];
if (self) {
}
return self;
}那么执行下面语句时，父类初始化时的self.lastName为什么会调用子类的setter
SmithPerson *p1 = [[SmithPerson alloc] init];解决方案1:
1、子类重写了getter/setter
@interface SmithPerson : Person
@end
@implementation SmithPerson
- (void)setLastName:(NSString *)lastName {
[super setLastName:lastName];
}
@end2、
self.lastName = @"abc";
//该方法等价于 [self setLastName:@"abc"];
//self 的类型为SmithPerson，所以会调用SmithPerson 类的 -setLastName: 方法