Is it okay to have many parameters in a void function in C++? [closed] - c++

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I'm a beginner so please be nice :)
I already make the program work properly with the use of Global Variables. But I want to try using Local Variables because the Global Variables looks messy and I also found out that it is a bad practice to always use it. The program runs with the Local Variables but it doesn't work properly. I'm having a problem with the display of the results which is under the void function funcDataSummary. The void funcDataSummary works and the values of (float numberOfRooms, float wallSpace, float costOfPaint,...) which are inputted by the user is correct but the values of (..., float gallonsOfPaint, float totalCostOfPaint, float hoursOfLabor, float laborCost, float totalCost) is 0 when they should have a value.
Output with the use of Global Variables:
Output with the use of Local Variables:
#include <iostream>
#include <iomanip>
#include <windows.h>
using namespace std;
// function prototype
void funcDataSummary(float, float, float, float, float, float, float, float);
// void function called in int main()
funcDataSummary(numberOfRooms, wallSpace, costOfPaint, gallonsOfPaint, totalCostOfPaint, hoursOfLabor, laborCost, totalCost);
// void function
void funcDataSummary(float numberOfRooms, float wallSpace, float costOfPaint, float gallonsOfPaint, float totalCostOfPaint, float hoursOfLabor, float laborCost, float totalCost)
{
cout << "DETAILS" << endl;
cout << "Number of Rooms = " << funcNumberOfRooms(numberOfRooms) << endl;
cout << "Wall Dimension = " << funcWallSpace(wallSpace) << " square feet" << endl;
cout << "Paint Cost = Php " << funcCostOfPaint(costOfPaint) << endl;
cout << "Gallons of Paint = " << funcGallonsOfPaint(gallonsOfPaint);
// singular and plural forms of units
if(funcGallonsOfPaint(gallonsOfPaint) > 1)
{
cout << " Gallons" << endl;
}
else
{
cout << " Gallon" << endl;
}
cout << "Total Paint Cost = Php " << << funcTotalCostOfPaint(totalCostOfPaint) << endl;
cout << "Labor hours = " << funcHoursOfLabor(hoursOfLabor);
// singular and plural forms of units
if(funcHoursOfLabor(hoursOfLabor) > 1)
{
cout << " hours" << endl;
}
else
{
cout << " hour" << endl;
}
cout << "Labor Cost = Php " << funcLaborCost(laborCost) << endl;
cout << "TOTAL COST = Php " << funcTotalCost(totalCost) << endl;
}

Answer 1

Though it's okay, it makes your code a bit complicated.
If it's possible, it's better group related to each other variables in one or more struct or class and pass these objects (or pointer/reference/const reference if it is needed) as parameters.

Answer 2

My suggestion is to use immutable class to store all kind of stuff you need in your function and pass it as a const reference or pointer. Here is an example :
#include <iostream>
#include <string>
#include <boost/noncopyable.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/make_shared.hpp>
class ParamsHolder : private boost::noncopyable
{
private :
std::string m_name;
std::uint32_t m_value;
public :
typedef boost::shared_ptr<ParamsHolder> pointer;
ParamsHolder( const std::string name, std::uint32_t value )
: m_name( name ), m_value( value ) {}
virtual ~ParamsHolder() {}
std::string getHolderName() const { return m_name; }
std::uint32_t getHolderValue() const { return m_value; }
};
void testFunction( ParamsHolder::pointer holder )
{
std::cout << holder->getHolderName() << std::endl;
std::cout << holder->getHolderValue() << std::endl;
}
int main()
{
std::cout << "Test program for holder" << std::endl;
std::string testName = "some name";
std::uint32_t testValue = 111;
auto holder = boost::make_shared<ParamsHolder>( testName, testValue );
testFunction( holder );
return 0;
}
To create a holder with many parameters have a look at builder design pattern or abstract factory.