Alloc/Dealloc objects

[Nobody/Anonymous]

Good morning, I'm a newbie;
Why this simple program:

#include <iostream>
#include <cstdlib>
using namespace std;

class Radio{
        int Volume;
        float Frequency;
      public:
        Radio();
        Radio(int InitV, float InitF);
        ~Radio();
        void SetVolume(int i);
        void SetFrequency(float f);
        int GetVolume(void);
        float GetFrequency(void);
        };
       
Radio::Radio(){
cout<<"Creates Radio object (with default)"<<endl;
Volume=5;
Frequency=105.500;
}
Radio::Radio(int InitV, float InitF){
cout<<"Creates Radio object (with parameters)"<<endl;
Volume=InitV;
Frequency=InitF;
}
Radio::~Radio(){
cout<<"Destructs Radio object"<<endl;
}
void Radio::SetVolume(int i){
   Volume=i;
}
void Radio::SetFrequency(float f){
   Frequency=f;
}
int Radio::GetVolume(){
   return Volume;
}
float Radio::GetFrequency(){
   return Frequency;
}       

/*******************************************************************/
void PrintParameters(Radio CustomRadio){
  cout<<"()Parameters :"<<endl;
  cout<<"\t()Volume = "<<CustomRadio.GetVolume()<<endl;
  cout<<"\t()Frequency = "<<CustomRadio.GetFrequency()<<endl;
}
/*******************************************************************/
int main(int argc, char *argv[])
{
  {
  Radio MyRadio;

  PrintParameters(MyRadio);
 
  Radio YourRadio(10,102.500);

  PrintParameters(YourRadio);

  }
  system("PAUSE");
  return 0;
}

return this :

Creates Radio object (with default)
()Parameters :
    ()Volume = 5
    ()Frequency = 105.5
Destructs Radio object
Destructs Radio object
Creates Radio object (with parameters)
()Parameters :
    ()Volume = 10
    ()Frequency = 102.5
Destructs Radio object
Destructs Radio object
Destructs Radio object
Destructs Radio object

2 Create and 6 Destruct ?

Thanks, Rene

[Nobody/Anonymous]

Have you heard of a copy construstor?  This is what is causing the extra destructs.  Add this code

//In Radio Class
Radio(const Radio &Org)//Org is the copy being passed in, New is the version you should normally return after changing it
{
     cout<<"In Copy Constructor\n";
}

goto  Ftp://66.222.198.62/Directory%20to%20Put%20Stuff%20in/CopyCnstr/  for an example  You will need MS Word

Now I have this as output:

Creates Radio object (with default)
In Copy Constructor
()Parameters :
        ()Volume = 1245056
        ()Frequency = 5.88665e-039
Destructs Radio object
Creates Radio object (with parameters)
In Copy Constructor
()Parameters :
        ()Volume = 10
        ()Frequency = 102.5
Destructs Radio object
Destructs Radio object
Destructs Radio object
Press any key to continue . . .

4 construct, and 4 destruct
The first two Destructs are for the copy construct

Hope this helps.

Curtis

[Nobody/Anonymous]

Thank you, but can you try the same original source with Visual C++ ? Once upon a time I tested it with a Visual C++ of my friend and I remember the output wasn't the same.
May be different directives compiler ?
Rene.

[Nobody/Anonymous]

That Code is VC++  I was at school with no Dev-Cpp :( 

Curtis