The Class LightBulb represents an electrical device that shines Consider the fol

Question

The Class LightBulb represents an electrical device that shines Consider the following diagrams below.

This instance was created by saying:

LightBulb offBulb( 60, false );

This instance was created by saying:

LightBulb onBulb;

Each LightBulb includes a wattage value and whether it is turned on or off. For the constructors shown above, here is the class definition (.h)

LightBulb( int wattage, bool isOn );

void light( );
void unlight( );

int getWattage( ) const;
bool isTurnedOn( ) const;

LightBulb(int wattage=50, bool isOn=true);

void light( ); // turn on the bulb

void unlight( ); // turn off the bulb

int getWattage( ) const;
bool isTurnedOn( ) const;

int myWattage;
bool myIsTurnedOn;

Based on the information shown here, a possible implementation (.cpp) for LightBulb is shown below.

LightBulb::LightBulb( int wattage, bool turnedOn ) :
          myWattage( wattage ), myIsTurnedOn( turnedOn )
{ // empty... }

int LightBulb::getWattage( ) const
{
return( myWattage );         
}

bool LightBulb::isTurnedOn( ) const      
{
return( myIsTurnedOn );
}

void LightBulb::light( )
{
myIsTurnedOn = true;         
}

void LightBulb::unlight( )               
{
myIsTurnedOn = false;        
}

Refrigerator r;          // fridge with currentTemp=60, light is off

Refrigerator r1( 40 ); // fridge with currentTemp=40, light is off

Refrigerator r2( 35, true ); // fridge with currentTemp=35, light on

In addition, create these two operations on Refrigerator:

void Refrigerator::openDoor();
void Refrigerator::closeDoor();

on Refrigerator which properly turns on its bulb when the door opens and turns its bulb off when the door closes.

This instance was created by saying:

LightBulb offBulb( 60, false );

This instance was created by saying:

LightBulb onBulb;

Explanation / Answer

/****chegg.h*****/
class LightBulb{
public:
   LightBulb(int wattage = 50, bool isOn = true);

   void light();
   void unlight();

   int getWattage() const;
   bool isTurnedOn() const;

private:
   int myWattage;
   bool myisTurnedOn;
};

class Refrigerator
{
public:
   Refrigerator(int temp = 60, bool turnedOn = false);

   void openDoor();
   void closeDoor();

   int getTemp() const;
   bool myisTurnedOn() const;

private:
   int currentTemp;
   LightBulb light;

  
};

/****chegg.cpp*****/

#include "chegg.h"
#include <iostream>

using namespace std;

LightBulb::LightBulb(int wattage, bool turnedOn): myWattage( wattage), myisTurnedOn(turnedOn)
{
//empty
}

int LightBulb::getWattage() const
{
return myWattage;
}

bool LightBulb::isTurnedOn() const
{
return myisTurnedOn;
}

void LightBulb::light()
{
myisTurnedOn = true;
}

void LightBulb::unlight()
{
myisTurnedOn = false;
}

Refrigerator::Refrigerator(int temp, bool turnedOn): currentTemp(temp)
{   
if(!turnedOn)
light.unlight();
}

void Refrigerator::openDoor()
{
light.light();
}
void Refrigerator::closeDoor()
{
light.unlight();
}
int Refrigerator::getTemp() const
{
return currentTemp;
}

bool Refrigerator::myisTurnedOn() const
{
return light.isTurnedOn();
}

int main()
{
LightBulb offBulb(60,false);
LightBulb onBulb;

Refrigerator r;
cout<<"fridge with currTemp = "<<r.getTemp()<<", light is "<<(r.myisTurnedOn()?"on":"off")<<endl;;

Refrigerator r1(40);
cout<<"fridge with currTemp = "<<r1.getTemp()<<", light is "<<(r1.myisTurnedOn()?"on":"off")<<endl;;

Refrigerator r2(35, true);
cout<<"fridge with currTemp = "<<r2.getTemp()<<", light is "<<(r2.myisTurnedOn()?"on":"off")<<endl;;

}

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