構造函數與析構函數（C++）

構造函數與析構函數（C++）

1. #include <iostream>
2. using namespace std;
3. enum BREED{ black, red, white, blue};
5. class mam{
6. public:
7. mam();
8. ~mam();
9. int get_age()const { return age; }
10. void set_age(int age1) {age = age1; }
11. int get_weight() const { return weight; }
12. void set_weight(int x) { weight = x; }
13. void speak() const { cout << "mam sound!\n"; }
14. void sleep() const {cout << "I'am sleeping.\n"; }
15. protected:
16. int age;
17. int weight;
18. };
20. class dog:public mam {
21. public:
22. dog();
23. ~dog();
24. BREED get_breed()const { return its_breed; }
25. void set_breed(BREED breed) { its_breed = breed; }
26. void wag_tail() const { cout << "Tail wagging...\n";}
27. void beg_for_food() const { cout << "begging for food...\n";}
28. private:
29. BREED its_breed;
30. };
32. mam::mam():age(3), weight(8) {
33. cout << "mam constructor..." << endl;
34. }
35. mam::~mam() {
36. cout << "mam destructor..." << endl;
37. }
38. dog::dog():its_breed(blue) {
39. cout << "dog constructor..." << endl;
40. }
41. dog::~dog(){
42. cout << "dog destructor..." << endl;
43. }
45. int main()
46. {
47. dog fido;
48. fido.speak();
49. fido.wag_tail();
50. cout << "fido is " << fido.get_age() << "years old" << endl;
51. // cout << fido.get_breed() <<endl;
52. // fido.set_breed(white);
53. // cout << fido.get_breed() << endl;
54. return 0;
55. }