#import <Foundation/Foundation.h>
@interface Person :NSObject{
    @public
    char *_name;
    int _age;
}
-(void) say:(NSString *) words;
@end
@implementation Person

-(void) say:(NSString *) words{
    NSLog(@"%@",words);
}
void changeAge(Person *person){
    person ->_age = 10;
    [person say:@"hello tom"];
}
@end
int main(int argc, const char * argv[])
{

    @autoreleasepool {

        Person *person = [Person new];
        person->_age = 1;
        changeAge(person);

        NSLog(@"age=%d",person->_age);

    }
    return 0;
}