#import "ViewController.h" @interface ViewController () @property (strong, nonatomic) NSMutableArray *numbersArray; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. self.numbersArray = [NSMutableArray new]; NSObject *o = [NSObject new]; [self.numbersArray addObject:o];//产生警告,incompatible pointer types sending 'NSObject*' to parameter of type 'NSNumber* _Nonnull' [self.numbersArray addObject:@(1)]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } @end