'double' to 'const std

[aquilina]

cannot convert from 'double' to 'const std::basic_string
its problem with the string material .. error at return material

void Greenhouse::setDescription(string material, int storey, double totalArea, double cleanFloorHeight){
	material=material;
	storey=storey;
	totalArea=totalArea;
	cleanFloorHeight=cleanFloorHeight;
}
	

string Greenhouse::getDescription(void){
	return material, storey, totalArea, cleanFloorHeight;
}

  //building.h file

#include<iostream>
#include<string>

using namespace std;

class Building
{
protected:
	string material;
	int storey;
	double totalArea;
	double cleanFloorHeight;

public:
	Building();
	string getMaterial(void);
	int getStorey(void);
	double getTotalArea(void);
	double getCleanFloorHeight(void);
	void displayAllBuilding();
};

class Greenhouse:public Building
{      
public:
	Greenhouse();
	void setDescription(string material, int storey, double totalArea, double cleanFloorHeight);
	string getDescription(void);
};

class Apartment:public Building
{      
public:
	Apartment();
	void setDescription(string material, int storey, double totalArea, double cleanFloorHeight);
	string getDescription(void);
};

class College:public Building
{      	
public:
	College();
	void setDescription(string material, int storey, double totalArea, double cleanFloorHeight);
	string getDescription(void);
};

class Classroom:public College
{      
public:
	Classroom();
	void setDescription(string material, int storey, double totalArea, double cleanFloorHeight);
	string getDescription(void);
};

class Gymnasium:public College
{      
public:
	Gymnasium();
	void setDescription(string material, int storey, double totalArea, double cleanFloorHeight);
	string getDescription(void);
};

class PoliceStation:public Building
{      
public:
	PoliceStation();
	void setDescription(string material, int storey, double totalArea, double cleanFloorHeight);
	string getDescription(void);
};

class Airport:public Building
{      	
public:
	Airport();
	void setDescription(string material, int storey, double totalArea, double cleanFloorHeight);
	string getDescription(void);
};

Building::Building(){}
string Building::getMaterial(void){
	return material;
}

int Building::getStorey(void){
	return storey;
}

double Building::getTotalArea(void){
	return totalArea;
}

double Building::getCleanFloorHeight(void){
	return cleanFloorHeight;
}

void Building::displayAllBuilding(){
	cout << "<-------------------Building------------------->" << endl;
	cout << endl;
	cout << "|1|                 Greenhouse                       " << endl;
	cout << "|2|                 Apartment                        " << endl;
	cout << "|3|                 College                          " << endl;
	cout << "|4|                 Police Station                   " << endl;
	cout << "|5|                 Airport                          " << endl;
	cout << "<--------------------------------------------------->" << endl;
	cout << endl;
	cout << endl;
}


Greenhouse::Greenhouse(){}

void Greenhouse::setDescription(string material, int storey, double totalArea, double cleanFloorHeight){
	material=material;
	storey=storey;
	totalArea=totalArea;
	cleanFloorHeight=cleanFloorHeight;
}
		
string Greenhouse::getDescription(void){
	return material, storey, totalArea, cleanFloorHeight;
}

Apartment::Apartment(){}

void Apartment::setDescription(string material, int storey, double totalArea, double cleanFloorHeight){
	material=material;
	storey=storey;
	totalArea=totalArea;
	cleanFloorHeight=cleanFloorHeight;
}
		
string Apartment::getDescription(void){
	return material, storey, totalArea, cleanFloorHeight;
}


College::College(){}

void College::setDescription(string material, int storey, double totalArea, double cleanFloorHeight){
	material=material;
	storey=storey;
	totalArea=totalArea;
	cleanFloorHeight=cleanFloorHeight;
}
		
string College::getDescription(void){
	return material, storey, totalArea, cleanFloorHeight;
}


Classroom::Classroom(){}

void Classroom::setDescription(string material, int storey, double totalArea, double cleanFloorHeight){
	material=material;
	storey=storey;
	totalArea=totalArea;
	cleanFloorHeight=cleanFloorHeight;
}
		
string Classroom::getDescription(void){
	return material, storey, totalArea, cleanFloorHeight;
}


Gymnasium::Gymnasium(){}

void Gymnasium::setDescription(string material, int storey, double totalArea, double cleanFloorHeight){
	material=material;
	storey=storey;
	totalArea=totalArea;
	cleanFloorHeight=cleanFloorHeight;
}
		
string Gymnasium::getDescription(void){
	return material, storey, totalArea, cleanFloorHeight;
}


PoliceStation::PoliceStation(){}

void PoliceStation::setDescription(string material, int storey, double totalArea, double cleanFloorHeight){
	material=material;
	storey=storey;
	totalArea=totalArea;
	cleanFloorHeight=cleanFloorHeight;
}
		
string PoliceStation::getDescription(void){
	return material, storey, totalArea, cleanFloorHeight;
}


Airport::Airport(){}

void Airport::setDescription(string material, int storey, double totalArea, double cleanFloorHeight){
	material=material;
	storey=storey;
	totalArea=totalArea;
	cleanFloorHeight=cleanFloorHeight;
}
		
string Airport::getDescription(void){
	return material, storey, totalArea, cleanFloorHeight;
}

[mutexe]

For basic data types you can only return one from a function, unless you wrap up the required set of data in a structure or class. (or pass in a reference or pointer for each 'out' value you require).

http://www.cplusplus.com/doc/tutorial/functions/