Why is this not working

mcoliver88 (57)
Hi all, could you tell me why this simple statement it not working, I am checking for char Y or y
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#include<iostream>
using namespace std;
int main()

{
	char ans;
	cout<<"test";
	cin>>ans;
	bool charvalid=false;
	do
	{
		if(ans!='Y'|| ans!='y')
		{
			cout<<"This is not a valid answer! \n";
			cout<<"Please try again using (Y/N) Only: ";
			cin>>ans;
		}
		else;
		{
			charvalid=true;
		}
	}while(charvalid);
	return 0;
}
Volatile Pulse (1329)
Switch the || in the if statement to &&.

You're checking to see if either statement is true, and a char can't be equal to to values.
jlillie89 (378)
I don't understand what your goal is ? I compiled it. What is the goal what is it not doing?
jlillie89 (378)
Maybe your else ? else; Loose the ;
mcoliver88 (57)
Thank you, so much. Would you be happy to test some code out for my from my program as i am having problems.

thanks
Michael
TheIdeasMan (1564)
Another good idea is to convert the char to upper case using std::toupper (need to #include locale to use it) - then you won't have to test it twice.

I personally hate construct like:

if(ans!='Y' && ans!='y')

especially if someone extends them to cope with other things like operators +-*/. This is best handled with a switch.
mcoliver88 (57)
my goal, was to check if the user enter Y or y if they didnt then they need to go back, and redo it to proceed further in the program
jlillie89 (378)
Did it work when you fixed the else?
mcoliver88 (57)
no when i add it to my entire program, it wont work. I will get a messgae saying that when i press Y its invalid and then after i use y it will proceed.

But if i restart the program and choose y i still get an error message
Volatile Pulse (1329) 
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#include<iostream>
using namespace std;
int main()

{
	char ans;
	cout<<"test";
	cin>>ans;
	bool charvalid=false;
	do
	{
		// if(ans!='Y'|| ans!='y') // Incorrect
		if(ans!='Y'&& ans!='y')
		{
			cout<<"This is not a valid answer! \n";
			cout<<"Please try again using (Y/N) Only: ";
			cin>>ans;
		}
		// else; // Incorrect
		else
		{
			charvalid=true;
		}
	}while(charvalid);
	return 0;
}


Myself and jlillie89 have already shown you how to fix it. If you're still having problems, you'll need to repost your code.
mcoliver88 (57)
I have added this code, to my larger program. here is the link too my code, i have put it on another post

http://www.cplusplus.com/forum/beginner/87480/

When i select option 2, and press Y i get the error message, if then press y, it will proceed to next line of code, however if i restart the program and go to option 2 and press y i get another error message
jlillie89 (378)
???? This work?

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#include<iostream>
using namespace std;



int main()
{
	char ans;
	 
	
	cout << "test ";
	cin >> ans;
	ans = toupper(ans);

	while( ans != 'Y')
	{
		cout << "This is not a valid answer! \n";
		cout << "Please try again using (Y/N) Only: ";
		cin >> ans;
		ans = toupper(ans);
	}
	system("pause");
	
	return 0;
}
mcoliver88 (57)
on its own yes, as soon as i put it in my program then the console screen froze
jlillie89 (378)
Well, as in it is waiting for something? Like _ ? Let's see it dude maybe I can help no promises I will look though if you post soon. The program I mean like where your putting it.
Last edited on
mcoliver88 (57)
Thanks guys for your help i really appreciate it:

http://www.cplusplus.com/forum/beginner/87480/

Thats the link to my full code, now the problem i have is placed into a function called validate() which is at the bottom. Now i have read that global variables are evil, which at the moment i am using loads. Could this be the problem?
mcoliver88 (57)
Also with the code, i am trying to use if for a menu....so

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int main()
{
	int choice;
	char ans;
	bool charvalid=false;
	//======================Menu===================================
	do
		{
			
		
		banner();
		//Prints out menu option
			cout<<"Welcome to the conference booking system:\n\n";
			cout<<"Option 1: Book A Seat\n";
			cout<<"Option 2: View Seating Plan\n";
			cout<<"Option 3: Exit\n\n";
			cout<<"Please choose an option: "; 			
			cin>>choice;
			switch(choice)
				{//Switch Open
				
					case 1://book seat
						{
							system ("cls");
							seatingPlan();
							bookSeat();
							break;
						}
					case 2://View seat plan
						{
							system ("cls");
							seatingPlan();
							seatPlan[row-1][convert-65];
							cout<<"Would you like to view the delegates, that have booked? (Y/N): ";
							cin>>ans;
							if(ans=='Y' && ans=='y')
							{
							delegates();
							}
							break;
						}
					case 3: //exit
						{
							cout<<"";
							return 0;
							break;
						}
					default: cout<<"Thank you for using This Booking System\n";
					break;

				}//switch closed
					cout<<"Do you want to return to main menu (Y/N):  ";
					cin>>ans;
					system ("cls");
	}while (ans='Y'|| ans=='y');// Loops back to the main menu


how could i get this code to work with the menu

Thanks
jlillie89 (378)
I did something like similar to this with a program I had to write. Maybe this will help you.

First is a function to get the input from the user.
I used something like this. Let me say there are easier way's to do this I assume. 

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//Function to display Menu and get selection
char displayMenu() 
{	
	//Variables
	char choice = ' ';

	//User menu
	cout << "Phone Directory Program " << endl;
	cout << endl;
	cout << "Options" << endl;
	cout << "[A]dd and entry to the phone directory. " << endl;
	cout << "[D]elete an entry from the phone directory. " << endl;
	cout << "[U]pdate an entry from the phone directory. " << endl;
	cout << "[L]ist the entire phone directory. " << endl;
	cout << "[E]xit the menu" << endl;
	//Get choice
	cout << "Please enter option selection. " << endl;
	cin >> choice;
	
	//Convert to uppercase
	choice = toupper(choice);
	
	//Control structure to return char to main.
	
	switch(choice)
	{
		case 'A': return 'A';
		break;
		case 'D': return 'D';
		break;
		case 'U': return 'U';
		break;
		case 'L': return 'L';
		break;
		case 'E': return 'E';
		default:  return 'F';
	}
}


Then in main I just switched on what came back from the function above.

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int main()
{	
	//Variables
	ifstream fin("input.txt");
	int newSize = 100;
    infoType tele[NSIZE];
	char selection = ' ';
	
    //Read from file
    readData(fin, tele, newSize );	
	
  //Main Algorithm
    do
	{
		system("cls");
		selection = displayMenu();
	
		//Function selection
	switch(selection)
	    {
		case 'A': update =  optionA(tele,newSize );
		break;
		case 'D': update = optionD(tele,newSize);
		break;
		case 'U': update =  optionU(tele,newSize );
		break; 	
		case 'L': optionL(tele,newSize );
		break;
		case 'E': update = EXIT;   
			break;	
		case 'F': cout << "Invaid choice " << endl;
		  Sleep(2000);  break;
		
	}
	
  }    while(update!= EXIT );
 
	system("pause");
 
 return 0;

}


Maybe this can help to give you an idea.
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