1. #import <Foundation/Foundation.h>
   
2. @interface Car :NSObject
   
3. {
   
4.     @public
   
5.     int wheels;
   
6.     int speed;
   
7. }
   
8. -(void)run;
   
9. void test(int w ,int s);
   
10. @end
    
11. 
    
12. @implementation Car
    
13. -(void)run
    
14. {
    
15.     NSLog(@"%d个轮子，时速为%dKm/h的车子跑起来了",wheels,speed);
    
16. }
    
17. 
    
18. @end
    
19. void test(int w ,int s)
    
20. {
    
21.     w =20;
    
22.     s =5;
    
23. }
    
24. 
    
25. 
    
26. int main()
    
27. {
    
28.     Car *p=[Car new];
    
29.     p->wheels = 4;
    
30.     p->speed = 200;
    
31.     test(p->wheels,p->speed);
    
32.     [p run];
    
33.     return 0;
    
34. }

复制代码

编译连接时出现问题：
localhost:11-OC mazhihua$ cc 09-OC对象和函数.m
Undefined symbols for architecture x86_64:
  "_NSLog", referenced from:
      -[Car run] in 09-OC对象和函数-83cd7b.o
  "_OBJC_CLASS_$_NSObject", referenced from:
      _OBJC_CLASS_$_Car in 09-OC对象和函数-83cd7b.o
  "_OBJC_METACLASS_$_NSObject", referenced from:
      _OBJC_METACLASS_$_Car in 09-OC对象和函数-83cd7b.o
  "___CFConstantStringClassReference", referenced from:
      CFString in 09-OC对象和函数-83cd7b.o
  "__objc_empty_cache", referenced from:
      _OBJC_METACLASS_$_Car in 09-OC对象和函数-83cd7b.o
      _OBJC_CLASS_$_Car in 09-OC对象和函数-83cd7b.o
  "_objc_msgSend", referenced from:
      _main in 09-OC对象和函数-83cd7b.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
localhost:11-OC mazhihua$


看不懂问题，不会解决，求指教！！

1. #import <Foundation/Foundation.h>
   
2. @interface Car :NSObject
   
3. {
   
4.     @public
   
5.     int wheels;
   
6.     int speed;
   
7. }
   
8. -(void)run;
   
9. void test(int w ,int s);
   
10. @end
    
11. 
    
12. @implementation Car
    
13. -(void)run
    
14. {
    
15.     NSLog(@"%d个轮子，时速为%dKm/h的车子跑起来了",wheels,speed);
    
16. }
    
17. 
    
18. @end
    
19. void test(int w ,int s)
    
20. {
    
21.     w =20;
    
22.     s =5;
    
23. }
    
24. 
    
25. 
    
26. int main()
    
27. {
    
28.     Car *p=[Car new];
    
29.     p->wheels = 4;
    
30.     p->speed = 200;
    
31.     test(p->wheels,p->speed);
    
32.     [p run];
    
33.     return 0;
    
34. }

复制代码

编译连接时出现问题：
localhost:11-OC mazhihua$ cc 09-OC对象和函数.m
Undefined symbols for architecture x86_64:
  "_NSLog", referenced from:
      -[Car run] in 09-OC对象和函数-83cd7b.o
  "_OBJC_CLASS_$_NSObject", referenced from:
      _OBJC_CLASS_$_Car in 09-OC对象和函数-83cd7b.o
  "_OBJC_METACLASS_$_NSObject", referenced from:
      _OBJC_METACLASS_$_Car in 09-OC对象和函数-83cd7b.o
  "___CFConstantStringClassReference", referenced from:
      CFString in 09-OC对象和函数-83cd7b.o
  "__objc_empty_cache", referenced from:
      _OBJC_METACLASS_$_Car in 09-OC对象和函数-83cd7b.o
      _OBJC_CLASS_$_Car in 09-OC对象和函数-83cd7b.o
  "_objc_msgSend", referenced from:
      _main in 09-OC对象和函数-83cd7b.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
localhost:11-OC mazhihua$


看不懂问题，不会解决，求指教！！