C++ invalid entry won't return

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hello and happy holidays to you all.

I am looking for some assistance with my C++ Code for a cellular bill program.

everything I have written so far works as I am wanting it to, except for 1 problem.

the issue that I am running into is that once an invalid entry is entered I receive the error prompt, but when the correct entry is entered it wont exit the loop and continue the program.

as a new student of C++, I am not seeing my error or the correct code. can somebody assist me with this please?

this is what I am getting while trying to run the program:

Welcome to Nates Wireless
Please enter your numeric account number: sdgf
Not an acceptable account number. Please try again.
123456
Not an acceptable account number. Please try again.

What I have tried:

here is my code:

C++

#include<iostream>
#include<iomanip>
#include<limits>

using namespace std;

int main()
{
	int accNum;
	int minutes, minutes2, minutes3;
	char serviceCode;
	double bill;

	const int INITIAL_REG = 10;
	const double REG_RATE = .2;
	const int REG_FREE = 50;
	const int INITIAL_PREM = 25;
	const double PREM_RATE1 = .1;
	const double PREM_RATE2 = .05;
	const int PREM_FREE1 = 75;
	const int PREM_FREE2 = 100;

	cout << "Welcome to Nates Wireless \n";
	cout << "Please enter your numeric account number: ";
	cin >> accNum;
	cin.ignore(numeric_limits<int>::max(), '\n');
	while ((!cin || cin.gcount() != 1))
	{
		cin.clear();
		cin.ignore(100, '\n');
		cout << "Not an acceptable account number. Please try again." << endl;
		cin >> accNum;
	}

	cout << "Please verify the type of service you have with us. \n";
	cout << "Enter \"r\" or \"R\" for Regular service or\n"; 
	cout << "\"p\" or \"P\" for Premium service: ";
	cin >> serviceCode;
	while (serviceCode != 'r' && serviceCode != 'R' && serviceCode != 'p' && serviceCode != 'P')
	{
		cin.clear();
		cin.ignore(100, '/n');
		cout << "Invalid service type. Please enter \"r\" or \"R\" for Regular or \"p\" or \"P\" for Premium." << endl;
		cin >> serviceCode;
	}

	cout << fixed << setprecision(2);

	switch (serviceCode)
	{
	case 'r':
	case 'R':
		cout << "Please enter the number of whole minutes you used: ";
		cin >> minutes;

		if (minutes == 0)
		{
			bill = INITIAL_REG;
			cout << "Regular account number " << accNum << " owes $" << bill << "." << endl;
			cout << "$" << INITIAL_REG << " initial service charge + $0 for 0 minutes used." << endl;
		}
		else if (minutes < REG_FREE && minutes > 0 || minutes == REG_FREE)
		{
			bill = INITIAL_REG;
			cout << "Regular account number " << accNum << " owes $" << bill << "." << endl;
			cout << "$" << INITIAL_REG << " initial service charge + $0 for a total of " << minutes
				<< " minutes of service." << endl;
		}
		else if (minutes > REG_FREE)
		{
			bill = INITIAL_REG + ((minutes - REG_FREE) * REG_RATE);
			cout << "Regular account number " << accNum << " owes $" << bill << "." << endl;
			cout << "$" << INITIAL_REG << " initial service charge + $" << ((minutes - REG_FREE) * REG_RATE)
				<< " for a total of " << minutes << " minutes of service." << endl;
		}
		else
			cout << "Can not use that value for minutes, please enter another value." << endl;
		break;
	case 'p':
	case 'P':
		cout << "Please enter the number of whole minutes you used between 6AM and 6PM: ";
		cin >> minutes2;
		while (minutes2 < 0)
		{
			cin.clear();
			cin.ignore(100, '\n');
			cout << "Invalid value for minutes. Please try again." << endl;
			cin >> minutes2;
		}

		cout << "Please enter the number of whole minutes you used between 6PM and 6AM: ";
		cin >> minutes3;
		while (minutes3 < 0)
		{
			cin.clear();
			cin.ignore(100, '\n');
			cout << "Invalid value for minutes. Please try again." << endl;
			cin >> minutes3;
		}

		if (minutes2 == 0 && minutes3 == 0)
		{
			bill = INITIAL_PREM;
			cout << "Premium account number " << accNum << " owes $" << bill << "." << endl;
			cout << "$" << INITIAL_PREM << " initial service charge + $0 for 0 minutes used." << endl;
		}
		else if (minutes2 == 0 && minutes3 > 0)
		{
			bill = INITIAL_PREM + ((minutes3 - PREM_FREE2) * PREM_RATE2);
			cout << "Premium account number " << accNum << " owes $" << bill << "." "\n";
			cout << "$" << INITIAL_PREM << " initial service charge + $" << ((minutes3 - PREM_FREE2) * PREM_RATE2)
				<< " for " << minutes3 << " minutes used between 6PM and 6AM." << endl;
		}
		else if (minutes3 == 0 && minutes2 > 0)
		{
			bill = INITIAL_PREM + ((minutes2 - PREM_FREE1) * PREM_RATE1);
			cout << "Premium account number " << accNum << " owes $" << bill << "." << endl;
			cout << "$" << INITIAL_PREM << " initial service charge + $" << ((minutes2 - PREM_FREE1) * PREM_RATE1)
				<< " for " << minutes2 << " minutes used between 6AM and 6PM. " << endl;
		}
		else if (minutes2 > 0 && minutes3 > 0)
		{
			bill = INITIAL_PREM + ((minutes2 - PREM_FREE1) * PREM_RATE1) + ((minutes3 - PREM_FREE2) * PREM_RATE2);
			cout << "Premium account number " << accNum << " owes $" << bill << "." << endl;
			cout << "$" << INITIAL_PREM << " initial service charge + $" << ((minutes2 - PREM_FREE1) * PREM_RATE1)
				<< " for " << minutes2 << " minutes used between 6AM and 6PM + $" << ((minutes3 - PREM_FREE2) * PREM_RATE2)
				<< " for " << minutes3 << " minutes used between 6PM and 6AM." << endl;
		}
		break;
	}

	return 0;
}

Posted 23-Dec-21 8:25am

nmeyer1

Updated 27-Dec-21 5:58am

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Comments

jeron1 23-Dec-21 16:01pm

while ((!cin || cin.gcount() != 1)) //what does this line do?

0x01AA 24-Dec-21 9:10am

Lazy and far away from perfect, still somethin like '33aa' will be accpeted:


#include <string>
#include <sstream>
//....
  string cinstr;
  int accNum= 0;
  
    cout << "Welcome to Nates Wireless \n";
	cout << "Please enter your numeric account number: ";  
    getline (cin,cinstr);
    stringstream(cinstr) >> accNum;
    while (accNum == 0)
    {
        cout << "Not an acceptable account number. Please try again." << endl;
        getline (cin,cinstr);
        stringstream(cinstr) >> accNum;
    }
    cout << accNum;
//

nmeyer1 27-Dec-21 9:31am

not really sure what that comment has to do with the assistance I was asking for, but thanks any way. I got it figured out.

0x01AA 27-Dec-21 10:12am

A more or less proper accNum input method, I think/thought :-)

3 solutions

Solution 1

While combining the results of logical operations we can make use of brackets in an appropriate manner.

C++

while ((!cin )||(cin.gcount() != 1))
	{
		cin.clear();
		cin.ignore(100, '\n');
		cout << "Not an acceptable account number. Please try again." << endl;
		cin >> accNum;
	}

Output:

Welcome to Nates Wireless 
Please enter your numeric account number: 1234
Please verify the type of service you have with us. 
Enter "r" or "R" for Regular service or
"p" or "P" for Premium service: ^C

Posted 24-Dec-21 2:13am

GirijaDhinakkarajan

Updated 24-Dec-21 2:41am

v2

Comments

nmeyer1 27-Dec-21 9:35am

thank you for pointing that out as that was one of the problems, and thank you for the assistance as I got it figured out and corrected.

Solution 2

thank you for the assistance, as i got it figured out.

this

while ((!cin || cin.gcount() != 1))

needed to be changed to this

while ((!cin) || (cin.fail()))

Posted 27-Dec-21 3:43am

nmeyer1

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merano99 · Accepted Answer · 2021-12-27T05:58:00

Instead of:

C++

cin >> accNum;
cin.ignore(numeric_limits<int>::max(), '\n');
while ((!cin || cin.gcount() != 1)) {
   cin.clear();
   cin.ignore(100, '\n');
   cout << "Not an acceptable account number. Please try again." << endl;
   cin >> accNum;
}

could you just write:

C++

while (!(cin >> accNum)) {
  cin.clear();
  cin.ignore(numeric_limits<streamsize>::max(), '\n');
  cout << "Not an acceptable account number. Please try again." << endl;
}

Not only would that be much shorter, it would also work as desired.