Any tips?

[Newie0001]

So I posted before asking for help about displaying my results but never got a reply. Anyway, I figured it out, I guess that what I want to know now is if there is a way that I can make my code better? Are there things that are not necessary or if there's a way to display things better? Or is my code fine as it is?

Initially this is what I had to do:


Create a function that displays the menu of gases and returns a character (or integer) that represents the choice made by the user. The function should validate the user's input to ensure it is a valid selection.

Create a function the accepts from the user the time traveled in seconds and validates the value before returning it.

Create a function that has two parameters - the gas and the time. The function should compute the distance and return it to the caller.

#include <iostream>
using namespace std;
// Constant declarations
// Speeds are in meters per second
const double CARBON_DIOX_SPEED = 258.0;
const double AIR_SPEED = 331.5;
const double HELIUM_SPEED = 972.0;
const double HYDROGEN_SPEED = 1270.0;

bool userWantsToContinue();
void displayMenu();
char acceptGas();
double convertGas(char gasType);
double acceptTime();
double computeDistance(double gasSpeed, double gasTime);
void  displayResults(char theGas, double theTime, double distance);

int main()
{
   do
   {
	   char theGas = acceptGas();
	   double theSpeed = convertGas(theGas);
	   double theTime = acceptTime();

	   double distance = computeDistance(theSpeed, theTime);
	   displayResults(theGas, theTime, distance);

   } while (userWantsToContinue());

    
    cout << "Please press ENTER to end program."; 
    cin.sync();
    getchar();
    return 0;
} 

bool userWantsToContinue()
{
	bool userChoice = false;
	bool validInput = false;
	char userInput = ' ';

	do
	{
		cout << "\n\nDo you want to continue? (y/n): ";
		cin >> userInput;

		validInput = (userInput == 'y') || (userInput == 'n');

	} while (!validInput);

	userChoice = (userInput == 'y');

	return userChoice;
}

void displayMenu()
{
	cout << "\n\n*********************************\n";
	cout << "Please select a gas: \n";
	cout << "\ta. Carbon Dioxide\n";
	cout << "\tb. Air \n";
	cout << "\tc. Helium\n";
	cout << "\td. Hydrogen\n";
	cout << "Choose a gas: ";
}

char acceptGas()
{
	char userGas = ' ';
	bool validInput = false;

	do
	{
		displayMenu();
		cin >> userGas;

		validInput = (userGas == 'a') || (userGas == 'b')
						|| (userGas == 'c') || (userGas == 'd');

		if (!validInput)
		{
			cout << "\nPlease enter a valid choice from the menu!\n";
		}

	} while(!validInput);

	return userGas;
}

double convertGas(char gasType)
{
	double gasSpeed = 0.0;
	if (gasType == 'a')
	{
		gasSpeed = CARBON_DIOX_SPEED;
	}
	else if (gasType == 'b')
	{
		gasSpeed = AIR_SPEED;
	}
	else if (gasType == 'c')
	{
		gasSpeed = HELIUM_SPEED;
	}
	else
	{
		gasSpeed = HYDROGEN_SPEED;
	}

	cout << endl << "Gas Speed: " << gasSpeed << endl;
	return gasSpeed;
}

double acceptTime()
{
	double userTime = 0.0;
	bool validInput = false;

	do
	{
		cout << "\n\nEnter the time for the sound ( 0 - 30 seconds): ";
		cin >> userTime;

		validInput = (userTime >= 0.0) && (userTime <= 30.0);

		if (!validInput)
		{
			cout << "\nPlease enter a valid time!\n";
		}

	} while(!validInput);

	return userTime;
}

double computeDistance(double gasSpeed, double gasTime)
{
		return gasSpeed * gasTime;
}
void  displayResults(char theGas, double theTime, double distance)
{
 cout << "\n\n*********************************\n";
 cout << "\t. The gas: " << theGas << endl;
 cout << "\t. The time: " << theTime << endl;
 cout << "\t. The distance: " << distance << endl;
}