Runtime3 - isKindOfClass、isMembe

OC的反射机制：反射最主要的目的是解耦。
isMemberOfClass：判断是否是某一个类
isKindOfClass：判断是否是某一个类或者该类的子类

类对象的比较：
//获取类对象
- (Class)class {
    return object_getClass(self);
}
//获取父类对象
- (Class)superclass {
    return [self class]->superclass;
}
//当前实例的类对象等于传入的类对象
- (BOOL)isMemberOfClass:(Class)cls {
    return [self class] == cls;
}
//当前实例的类对象等于传入的类对象/或者当前实例的父类对象等于传入的类对象
- (BOOL)isKindOfClass:(Class)cls {
    for (Class tcls = [self class]; tcls; tcls = tcls->superclass) {
        if (tcls == cls) return YES;
    }
    return NO;
}

元类对象的比较：
+ (Class)class {
    return self;
}
+ (Class)superclass {
    return self->superclass;
}
+ (BOOL)isMemberOfClass:(Class)cls {
    return self->ISA() == cls;
}
+ (BOOL)isKindOfClass:(Class)cls {
    for (Class tcls = self->ISA(); tcls; tcls = tcls->superclass) {
        if (tcls == cls) return YES;
    }
    return NO;
}


实例1:
    - (void)question1 {
    //NSObject基类的元类对象的superclass是NSObject基类的类对象
    BOOL result1 = [[NSObject class] isKindOfClass:[NSObject class]];   //YES
    BOOL result2 = [[NSObject class] isMemberOfClass:[NSObject class]]; //NO
    BOOL result3 = [[Person class] isKindOfClass:[Person class]];      //NO
    BOOL result4 = [[Person class] isMemberOfClass:[Person class]];    //NO
    NSLog(@"result1 = %d", result1); //1
    NSLog(@"result2 = %d", result2); //0

    NSLog(@"result3 = %d", result3); //0
    NSLog(@"result4 = %d", result4); //0
    
    Person *person = [[Person alloc] init];
    NSLog(@"结果1:%d", [person isMemberOfClass:[Person class]]);   //1
    NSLog(@"结果2:%d", [person isMemberOfClass:[NSObject class]]); //0
    NSLog(@"结果3:%d", [person isKindOfClass:[Person class]]);    //1
    NSLog(@"结果4:%d", [person isKindOfClass:[NSObject class]]);  //1
}