Simple function pointer example

1. # Include <stdio. h>
2. Typedef void (* bottle_type) (int I); // we have designed a bottle model here. This bottle is not easy. You can install any starting function address! Let's use it to create a bottle.
4. Void vinegar (int I) // vinegar
5. {
6. Printf ("% d: Now, I am vinegar, not bottle! /N ", I );
7. }
9. Void soy (int I) // soy sauce
10. {
11. Printf ("% d: Now, I am soy, not bottle and vinegar! /N ", I );
12. }
14. Int main ()
15. {
16. Bottle_type bottle; // a bottle is created based on the bottle_type model.
17. 
    
18. Bottle = vinegar; // Add vinegar to the bottle. Will you still call it a bottle? If yes, I don't believe it. If you go to the supermarket to buy vinegar, you will point to the vinegar and say to the vending lady, I want to buy this bottle ^-^! (Actually, the vinegar address is installed in the bottle)
20. (* Bottle) (1); // because the bottle contains vinegar, the result is also vinegar.
22. Bottle = soy; // It's too sour to add vinegar now! Add soy sauce. Will you still call it a bottle or vinegar? It's called soy sauce (soy address is installed in the bottle)
24. (* Bottle) (2); // bottle is soy sauce.
25. Return 0;
26. }

Liulife @ liulife :~ /Test $ gcc-O test_func_p test_func_p.c

Liulife @ liulife :~ /Test $ ls
Test_func_p test_func_p.c

Liulife @ liulife :~ /Test $./test_func_p
1: Now, I am vinegar, not bottle!

2: Now, I am soy, not bottle and vinegar!