Problem with run agin loop

[marfur]

I'm having problem with the loop that asks the user if she/he want to run the program again. When I input something else then Y or N the program gets in an infinite loop, how can I fix that?

int main()
{
    char ch;
    
    do
    {
        string Start,End;
        
        cout<<"Some content: ";
        getline(cin, Start);
        
        cout<<"Some content: ";
        getline(cin, End);
        
        cout<<convert(Start,End)<<" kr" << endl;
        
        cout << "Run program again(y/n)? ";
        
        cin >> ch;
        cin.ignore(250,'\n');
        do
        {   ch = toupper(ch);
        } while ( !(ch == 'Y' || ch == 'N'));
    } while (ch == 'Y');
    return 0;   
}

[2kaud]

do
{
    ch = toupper(ch);
} while ( !(ch == 'Y' || ch == 'N'));

Within the loop, where do you obtain a new input from the user if the input is not as expected?

[marfur]

@2kaud nowhere I guess

[2kaud]

@2kaud nowhere I guess

Yep - that's why you get an infinite loop. If the input isn't as required then you need to display an error message and re-prompt the user and obtain input again.

[marfur]

Okay thanks @2kaud ! How do I do if I want to end the program regardless of what the user inputs except Y?

[2kaud]

How do I do if I want to end the program regardless of what the user inputs except Y?

That's not what your original code was trying to achieve - and the user prompt does ask for y/n. However, if any answer will do and only loop again if Y entered then consider

	char ch;
	do {
		//rest of program here

		cout << "Run program again(y/n)? ";
		cin >> ch;
	} while (toupper(ch) == 'Y');

However, if you want it as per your original, then consider

	char chu;
	do {
		//rest of program here

		do {
			char ch;
			cout << "Run program again(y/n)? ";
			cin >> ch;
			chu = toupper(ch);
			if ((chu != 'N') && (chu != 'Y'))
				cout << "Invalid input." << endl;

		} while ((chu != 'N') && (chu != 'Y'));
	} while (chu == 'Y');