How do I check one variable before inputting the others on the same line?

[eyeless71]

	cout << "Enter a phone number(Enter Q to quit): ";
		cin >> a >> b >> c >> d >> e >> f >> g >> h;

In this program I'm trying to get a phone number. If the user enters a q it's supposed to exit. The program is for a programming class and the instructor wants us to not use arrays. The problem is, if the user enters a q, the program still wants the other 7 variables. I can't make 8 separate cin statements. The program won't exit when I enter a q, and I can't figure out how to fix this problem.

[Chervil]

I can't make 8 separate cin statements.

Not sure quite what this means. I assume there are certain restrictions on how the project is to be approached.

For example are you allowed to use a string?
What constitutes a phone number, can it include spaces or hyphens etc?

[ats15]

http://www.cplusplus.com/reference/istream/istream/peek/

[MiiNiPaa]

#include <iostream>

struct phone
{
    int a, b, c, d, e, f ,g, h;
};

int main()
{
phone number;
unsigned index(0);
while(std::cin >> *(&(number.a) + index++)) //Using POD structs
    if (index == 8) break;                  //No undefined behavior here.
if(std::cin.good())
    std::cout << number.a << ' ' << number.b << ' ' << number.c << ' ' << 
                 number.d << ' ' << number.e << ' ' << number.f << ' ' << 
                 number.g << ' ' << number.h;
}

[JLBorges]

> How do I check one variable before inputting the others on the same line?

Read the first variable && check it to see if we should proceed && read the remaining variables.

Or: Read the first variable if we should proceed is true then read the remaining variables.

#include <iostream>

int main()
{
    char a,b,c,d,e,f,g,h ;

    while(  std::cout << "Enter a phone number(Enter Q to quit): " &&
            std::cin >> a && a != 'Q' && a != 'q' &&
            std::cin >> b >> c >> d >> e >> f >> g >> h )
    {
        // whatever
    }
}

[eyeless71]

@Chervil - These are the rules for the project:

Write a program that simulates the dialing of a phone number.

A user will input an 8-place number, for example: 359-3177 (note that the hyphen is considered a digit).
The rules for entering phone numbers follow.

• 8 places
• It may have numbers, letters, or both.
• The phone number cannot begin with 555.
• The phone number cannot begin with 0.
• The hyphen must be in the 4th position.
• No other characters (@#$%^&*()_+=\|/><etc.) are allowed.
• If a letter is entered, its output will be a number (check your phone pad).
• Enter Q to Quit.

The focus of this project is supposed to be on functions. We are to use a readDials function to input the phone number, a toDigit function to convert the user input into numbers, and an acknowledgeCall function to output the number. The instructions specifically say to make 8 separate char variables and not to use an array.

[gobiking]

He won't be able to use 'q' to quit. Because there is a chance the number has a q in it. So you may want to prompt ppl to use lower case letters when inputting a letter. After tinkering with this the code I got to work was this. I truncated it to save some space.

#include <iostream>

using namespace std;

char num1,num2,num3,num5,num6,num7,num8;
char num4 = '-';

void toDigit(char)
{
	 if (num1=='a' || num1 =='b' || num1 == 'c')
		 num1='2';
	 if (num1=='d' || num1 =='e' || num1 == 'f')
		 num1='3';
	 if (num1=='g' || num1 == 'h' || num1 == 'i')
		 num1='4';
	 if (num1=='j' || num1 == 'k' || num1 =='l')
		 num1='5';
	if (num1=='m'||num1=='n'||num1=='o')
		num1='6';
	if (num1=='p'||num1=='q'||num1=='r'||num1=='s')
		num1='7';
	if (num1=='t'||num1=='u'||num1=='v')
		num1='8';
	if (num1=='w'||num1=='x'||num1=='y'||num1=='z')
		num1='9';

	if (num2=='a' || num2 =='b' || num2 == 'c')
		 num2='2';
	 if (num2=='d' || num2 =='e' || num2 == 'f')
		 num2='3';
	 if (num2=='g' || num2 == 'h' || num2 == 'i')
		 num2='4';
	 if (num2=='j' || num2 == 'k' || num2 =='l')
		 num2='5';
	if (num2=='m'||num2=='n'||num2=='o')
		num2='6';
	if (num2=='p'||num2=='q'||num2=='r'||num2=='s')
		num2='7';
	if (num2=='t'||num2=='u'||num2=='v')
		num2='8';
	if (num2=='w'||num2=='x'||num2=='y'||num2=='z')
		num2='9';
// u get the idea...
}
	

void readDials()
{
	cin>>num1;
		toDigit(num1);
	cin>>num2;
		toDigit(num2);
	cin>>num3;
		toDigit(num3);
	cin>>num5;
		toDigit(num5);
	cin>>num6;
		toDigit(num6);
	cin>>num7;
		toDigit(num7);
	cin>>num8;
		toDigit(num8);
}


void acknowledgeCall()
{
	cout<<num1<<num2<<num3<<num4<<num5<<num6<<num7<<num8<<endl;

}
int main ()
{
	cout<<"Please enter in the phone number."<<endl;
	cout<<"When inputing letters please use lower-case"<<endl;
	cout<<"Type 'Q' when you would like to quit"<<endl;
	do
         {
         readDials();
	acknowledgeCall();
	cout<<"Please enter in another phone number."<<endl;
	}
        while (num1 !='Q');

}

wish i could of made the code shorter but couldnt use arrays, dont know why your professor doesn't want you to use them. If you are just gonna use this a tip to type in the other num rules is to highlight the info paste it a bunch of times highlight em again go to edit and do replace num1 with num whatever then do selection and replace all.