Objective-C 类型判断

可以通过 isKindOfClass 判断对象的类型

 @interface A : NSObject

 @end
 @implementation A

 @end
 ////
 @interface AA : A

 @end
 @implementation AA

 @end
 ////
 @interface B : NSObject

 @end
 @implementation B

 @end
 int main(int argc, char * argv[]) {
     A *a = [[A alloc]init ];
     // 运行结果1
     NSLog(@"%d",[a isKindOfClass:[NSObject class]]);

     @autoreleasepool {
         return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
     }
 }