Re: myCar.acUnit.SwitchOn();

From:

"Jim Langston" <tazmaster@rocketmail.com>

Newsgroups:

comp.lang.c++

Date:

Fri, 2 Nov 2007 20:20:03 -0700

Message-ID:

<3MRWi.1095$144.367@newsfe02.lga>

"gccntn" <gccntn@yahoo.com> wrote in message
news:1194033351.229940.191610@19g2000hsx.googlegroups.com...

On 2 Nov, 03:48, "Jim Langston" <tazmas...@rocketmail.com> wrote:

"gccntn" <gcc...@yahoo.com> wrote in message

news:1193981449.606045.68850@v3g2000hsg.googlegroups.com...

I know the subject of the post is a bit cryptic, but here is what I'd
like my code to look like:

int main()
{
  Car myCar;
  myCar.Start();
  myCar.acUnit.SwitchOn(); // invoke TurnOn(), method of class
AC, which is a member of class Car
  myCar.acUnit.SetTemp(75); // invoking SetTemp(), method of class
AC, which is a member of class Car
   ...etc...
myCar.Stop();
  return 0;
}

How should I declare classes Car and AC?

The way I see things, this is what the declarations would look like:

class AC
{
  public:
     SwitchOn();
     SwitchOff();
     SetTemp();
     GetTemp();
  private:
  ...etc...
}

class Car
{
  public:
     Start();
     Stop();
  ...etc...
  <access_specifier>:
     AC acUnit;
     Engine engine;
  ...etc...
}

What should <access_specifier> be so that I can invoke AC's methods
from a Car as outlined in the code above?

public.- Nascondi testo tra virgolette -

- Mostra testo tra virgolette -

What if I wanted to grant Car's methods access to AC's methods, BUT I
did NOT want users of the Car class to have access to all the methods
in AC?

For instance, while I would a Car to initialize the AC:

bool Car::Start()
{
acUnit.Initialize(); // I WANT TO ALLOW THIS
...etc...
}

I would NOT want someone to initialize acUnit via the Car class:

int main()
{
  Car myCar;
  myCar.acUnit.Initialize(); // NO!!!
  ...etc...
}

Any suggestions? Thanks again for your help.

Encapsulation.

class Car
{
public:
void SwitchOnAC() { acUnit.switchon(); }
private:
AC acUnit;
};