isKindOfClass、isMemberOfClass

+(BOOL) isKindOfClass: (Class)aClass: aClass为self的元类对象，或者元类对象的父对象，才返回YES
-(BOOL) isKindOfClass: (Class)aClass：如果self为实例对象，aClass传入的是类对象或者类对象的父对象时，或者self为类对象，aClass为元类对象或者元类对象的父对象时，才返回YES
+(BOOL) isMemberOfClass: (Class)aClass：aClass为self的元类对象，才返回YES
-(BOOL) isMemberOfClass: (Class)aClass：如果self为实例对象，aClass传入的是类对象，或者self为类对象，aClass为元类对象，才返回YES

• isKindOfClass和isMemberOfClass的共通点是self与aClass的关系，即：
  aClass、object_getClass(self)进行比较
• 苹果官方对外暴漏的API中没有+(BOOL) isKindOfClass: (Class)aClass和+(BOOL) isMemberOfClass: (Class)aClass两个类方法，但其实是有的，以下方法可以猜想并验证
  
  如何查看方法类型01.png
  
  
  如何查看方法类型02.png

或者通过控制台打印IMP查看

如何查看方法类型03.png

以下是模拟内部实现的代码

int GSObjCIsKindOf(Class cls, Class other)
 {
 while (cls != Nil)
 {
 if (cls == other)
 {
 return YES;
 }
 cls = class_getSuperclass(cls);
 }
 return NO;
 }

+ (BOOL) isKindOfClass: (Class)aClass
{
    Class class = object_getClass(self);
    return GSObjCIsKindOf(class, aClass);
}

- (BOOL) isKindOfClass: (Class)aClass
{
    Class class = object_getClass(self);

    return GSObjCIsKindOf(class, aClass);
}

+ (BOOL) isMemberOfClass: (Class)aClass
{
    Class class = object_getClass(self);
    return (class == aClass) ? YES : NO;
}

- (BOOL) isMemberOfClass: (Class)aClass
{
    Class class = object_getClass(self);
    return (class == aClass) ? YES : NO;
}