Inheritance

[DrunkenTiger]

I am building a simple program, using classes I have to create a main building class and make some derived classes based on the building.

I have created the base class, and have tried to create one derived class using some examples found on the internet but it seems to be giving me a bunch of compile errors. This is my latest attempt.

//Building.h

#ifndef BUILDING_H
#define BUILDING_H

//Main building class which will be used as template to inherit other classes.
class Building	{
public:
	Building()	{ Rooms = 0; Floors = 0; Area = 0; Heating = 'e'; }					//Constructor
	~Building();     			//Destructor
	
	//Sets the number of rooms for the building
	void setRooms( int );
	
	//Sets the number of floors for the building
	void setFloors( int );
	
	//Sets the area for the building
	void setArea( int );
	
	//Sets the heating type for the building
	void setHeating( char );

	//Accessor function to retreive current value
	void getValue( int );

	//Prints the value of Building
	void Print();
protected:
	int Rooms;
	int Floors;
	int Area;
	char Heating;
};

#endif	//BUILDING_H

member functions.

//Building.cpp

#include "Building.h"

#include <iostream>
 
using std::cout;
using std::cin;
using std::endl;


	///Destructor for building class

Building::~Building()	{
	cout << "Building object destroyed!" << endl;
}

	///sets the value of int Rooms,floors and area in the building class.
	///function accepts 1 parameter, which will be validated
	///if the value is greater then 1 and less then 1000 it's
	///all good otherwise it will be a default of 0.

void Building::setRooms( int x )	{
	Rooms = ( x >= 0 && x < 1000 ) ? x : 0;
}

void Building::setFloors( int x )	{
	Floors = ( x >= 0 && x < 1000 ) ? x : 0;
}

void Building::setArea( int x )	{
	Area = ( x >= 0 && x < 10000 ) ? x : 0;
}

void Building::setHeating( char h )	{
	switch( h )	{
		//case 'e'
		case 'E':
			Heating = h;
			break;
		//case 'o'
		case 'O':
			Heating = h;
			break;
		default:
			cout << "Invalid value entered!  Please make another selection." << endl;
			Heating = 'e';
			break;
	}
}

void Building::getValue( int x )	{
	switch ( x )	{
		case 1:
			cout << "The value of Rooms is: " << Rooms << endl;
			break;
		case 2:
			cout << "The value of Floors is: " << Floors << endl;
			break;
		case 3:
			cout << "The value of Area is: " << Area << endl;
			break;
		case 4:
			cout << "The value of Heating is: " << Heating << endl;
			break;
		default:
			cout << "Incorrect value entered.  Please make another selection." << endl;
			break;
		}
}

void Building::Print()	{
	cout << "Building specifications:  " << endl;
	cout << "Rooms  : " << Rooms << endl;
	cout << "Floors : " << Floors << endl;
	cout << "Area   : " << Area << endl;
	cout << "Heating: " << Heating << endl;
}

this is my derived class.

//School.h

#ifndef SCHOOL_H
#define SCHOOL_H

#include "Building.h"

class School : public Building	{
public:
	School( int, int, int, char, int, int, int );
	~School();
	void setWashrooms( int );
	void setClassrooms( int );
	void setOffices( int );
protected:
	int Washrooms;
	int Classrooms;
	int Offices;
}

#endif	//SCHOOL_H

it gives me problems compiling the functions for my derived class.

#include "School.h"

void School::setWashrooms( int x )	{
	Washrooms = ( x >= 0 && x < 1000 ) ? x : 0;
}

void School::setClassrooms( int x )	{
	Classrooms = ( x >= 0 && x < 1000 ) ? x : 0;
}

void School::setOffices( int x )	{
	Offices = ( x >= 0 && x < 1000 ) ? x : 0;
}

Can you help me find out what im doing wrong. I've looked at a ton of tutorials on the net. Thanks.

[Dohojar]

Can you post the errors you are getting.

[jinhao]

It's here, you are missing a semicolon

//School.h

#ifndef SCHOOL_H
#define SCHOOL_H

#include "Building.h"

class School : public Building	{
public:
	School( int, int, int, char, int, int, int );
	~School();             //this is a warning,you don't define the destructor 
	void setWashrooms( int );
	void setClassrooms( int );
	void setOffices( int );
protected:
	int Washrooms;
	int Classrooms;
	int Offices;
}           //here miss a ;

#endif	//SCHOOL_H

[DrunkenTiger]

Thanks. I'm going to have to read up more on destructors. I'm having alittle trouble using my derived class in my program. I'm getting (1) compile error

"c:\desktop\project\main.cpp(16) : error C2512: 'School' : no appropriate default constructor available"


I'm using this as my constructor for my class.

School( int, int, int, char, int, int, int ) : Building(){};

this is where my compiler (msvc++ 6.0) throws the error.
in my main.cpp. Where i do a simple:

School s; // This is the trouble line.

Am i constructing my class incorrectly?

[jinhao]

yes,you must get a default constructor when you School s;

//School.h

#ifndef SCHOOL_H
#define SCHOOL_H

#include "Building.h"

class School : public Building	{
public:
                School(){};    //here,offer a default constructor
	School( int, int, int, char, int, int, int );
	~School();
	void setWashrooms( int );
	void setClassrooms( int );
	void setOffices( int );
protected:
	int Washrooms;
	int Classrooms;
	int Offices;
};

#endif	//SCHOOL_H

[DrunkenTiger]

Excellent, thanks for the help man. So I didn't need to have the lame constructor that I had in place already? My derived class will use the base classes constructor, and then use it's own default constructor to finish up it's creation?

[jinhao]

yes,School( int, int, int, char, int, int, int ); is a useless constructor and is not a default constructor

School s; this will call the default constructor

The compiler will not insert a default construct for the class school.because the constructor School(int, int, int, char, int, int, int )is existing.
now you must write a default constructor by yourself or you could
declare School( int a=1, int b=1, int c=1, char d=1, int e=1, int f=1, int g=1 ); to make the constructor into a default constructor
be careful,a class must have a default constructor existing.

[DrunkenTiger]

Great, that clears alot up for me. Thanks for the help.