CODEWITHSUNDEEP
c++destructor
Vitali K
Vitali K

Reputation: 607

c++, have problems with destructor

I have such code:

#include <iostream>

using namespace std;

class X
{
    int a;
public:
    X()
    {
        cout<<"X constructor was called"<<endl;
    }
    X(int n)
    {
        cout<<"X(int) constructor was called"<<endl;
    }
    ~X(){cout<<"X dectructor was called"<<endl;}
};
int main()
{
    X x(3);

    system("PAUSE");

    return 0;
}

The result of this code execution is: X(int) constructor was called . But why the destructor message have not been printed?

As I understand, we create object x by calling constructor X(int) and in the end of the program this object have to be deleted, but it did not.

Upvotes: 2

Views: 550

Answers (4)

Matthieu Rouget
Matthieu Rouget

Reputation: 3369

Try this :

int main()
{
    {
       X x(3);
    } // Your x object is being destroyed here

    system("PAUSE");

    return 0;
}

It will create a local scope for X, so that you see X being destroyed.

Upvotes: 1

Cyrille
Cyrille

Reputation: 14523

Since it's allocated on stack, Destructor should be called here:

int main()
{
    X x(3);

    system("PAUSE");

    return 0;
} // X destructor (x go out of context)

Upvotes: 3

jrok
jrok

Reputation: 55395

The destructor is run when the object goes out of scope. I'm guessing you put system("pause") to see its message. Well no, the scope of x didn't yet end there, it ends after return 0;.

Run your program from the terminal and see for yourself.

Upvotes: 2

user123
user123

Reputation: 9071

The destructor will not be called until the object is out of scope, and that's not going to happen until you exit main.

This is why the message doesn't pop up: The console is gone by the time the object is gone.

Upvotes: 1

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