Constructor/destructor

[Deanm007]

The code below does not show the output when the destructor is called. It shows when the constructor is called, then it shows the age. Then it finishes. Am I doing something wrong here? Thanks

 #include <iostream>
 
 using namespace std;
 
 enum BREED { YORKIE, CAIRN, DANDIE, SHETLAND, DOBERMAN, LAB}; //global enumeration


 class Mammal //This is the base class 
 {
    public:
           
 // constructors
 Mammal();
 ~Mammal();

 //accessor methods
 int GetAge()const {return itsAge;}
 void SetAge(int age){itsAge = age;}
 int GetWeight() const {return itsWeight;}
 void SetWeight(int weight){itsWeight = weight;}

 //Other methods
 void Speak() const {cout << "Talking" << endl;}
 void Sleep()const {cout << "Sleeping" << endl;}


 protected: 
            
 int itsAge;
 int itsWeight;
 };

 class Dog : public Mammal
 {
 public:

 // Constructors...dog class must have its own constructor //and destructor.

 Dog();
 ~Dog();

 // Accessor methods
 BREED GetBreed() const {return itsBreed;} 
 void SetBreed(BREED breed){itsBreed = breed;} 
 // Other methods
 void WagTail(){cout << "Tail wagging..." << endl;}
 void BegForFood(){cout << "Begging for food..." << endl;}

 protected:
 BREED itsBreed; 
 };
 
  Mammal::Mammal()
  {
  itsAge=1; 
  itsWeight=5;
  cout<<"Mammal constructor called" << endl; 
  } 
 
  Mammal::~Mammal()
  {
  cout<<"Mammal destructor called" << endl;
  }
  
  Dog::Dog()
  {
  itsBreed = YORKIE;
  cout << "Dog constructor called" << endl;
  
  }
  
  Dog::~Dog()
  {
  cout<<"Dog destructor called" << endl;
  }
  
 
 int main()
 {
     Dog Benny; 
     Benny.Speak();
     Benny.BegForFood();
     Benny.SetAge(56); 
     cout << "Benny is " << Benny.GetAge() << " years old." << endl;
     
     
     system("pause");
     return 0;
     
 }

[Banfa]

It wont show any output for the destructor because the destructor is not called until until main exits and the object is destroyed.

Remove the system("pause") ;, which is bad practice anyway and run the program in a way doesn't involve the command prompt disappearing when the program exits (Ctrl-F5 in MSVC or find your IDEs method to run the program rather than debug it or just start a command prompt and run it).

[newb16]

output using gcc 3.4.4 (cygwin) :

Mammal constructor called
Dog constructor called
Talking
Begging for food...
Benny is 56 years old.
Dog destructor called
Mammal destructor called

as expected.

[weaknessforcats]

the destructor is not called until until main exits and the object is destroyed.

Maybe.

The compiler may call the destructor any time after the object is marked for destruction (goes out of scope or you delete yourself). This may be right away or perhaps at the end of main. There's no way to know unless your destructor tells you it has been called.

[Deanm007]

Banfa, as you mentioned, I got rid of system pause and did ctrl+f10 on dev c++ and the prompt just does not stay up. So I kept holding ctrl+f10 and I saw a glimpse of the destructor being called. Also, I tried it in MSVC (without system pause or cin.get()) with ctrl+f5 and it shows the destructor being called. So I understand that the destructor is called only when the object is destroyed or when main exits and main does not exit if you have system pause statement in there. Thank you very much.