getchar() problem (also conio.h)

graemef · 09-05-2008, 01:34 AM

you may want to try adding a \r whenever you have a \n.

dmail · 09-05-2008, 10:17 AM

The following will work fine using only the standard library.

Code:

#include <iostream>

void print_question(int const& x,int const& y)
{
	std::cout << "\nYour coordinates are: \n" << x << ", " << y << ".\n"
	<< "Enter the direction you like: (n,s,e,w)" <<std::endl;
}

int main()
{
	char dir;
	int x = 10, y = 10;
	print_question(x,y);

	while (std::cin.peek() != '\n')
	{
		std::cin >>dir;
		std::cin.ignore(10000 , '\n');
		switch(dir)
		{
			case 'n': y++; break;
			case 's': y--; break;
			case 'e': x++; break;
			case 'w': x--; break;
			default: std::cout << "You made a mistake! Try again " <<std::endl;
		}
		print_question(x,y);
	}
	std::cout <<"Exiting the program, bye bye!" <<std::endl;
	return 0;
}

faizlo · 09-06-2008, 12:19 AM

Hi All,

dmail, your code worked fine. I am studying it.
I have a couple of questions:
Why did you have

Code:

void print_question(int const& x,int const& y)
{
	std::cout << "\nYour coordinates are: \n" << x << ", " << y << ".\n"
	<< "Enter the direction you like: (n,s,e,w)" <<std::endl;
}

outside main() function? And why not use

Code:

using namespace std;

(I know it might be your way of writing codes, I just want to make sure I follow everything here.

And Is this the solutions to conio.h problem in Linux?

As I said I am using Robert Lafore's book (Object Oriented programming using C++) from Waite Group, 3rd edition. And it seems he wrote it for Windows. I love the book but I have to find a solution to this conio.h problem.

A small note:
Whenever Microsoft introduces something, it just makes life more difficult. If they can't play by the rules (ISO/ANSI) they should quit!

faizlo

faizlo · 09-06-2008, 12:30 AM

graemef, I have tried replacing \n with \r and I got the first line (asking about the direction) and nothing happens whenever I press n,e,s,w. but it quits when I use q.

faizlo

dmail · 09-06-2008, 05:32 AM

Quote:

Originally Posted by faizlo

Hi All,

dmail, your code worked fine. I am studying it.
I have a couple of questions:
Why did you have

Code:

void print_question(int const& x,int const& y)
{
	std::cout << "\nYour coordinates are: \n" << x << ", " << y << ".\n"
	<< "Enter the direction you like: (n,s,e,w)" <<std::endl;
}

outside main() function?

The reason I included the printing of the question in a function is that it is called in two different places in the code I provided, it would be redundant to write the code twice.

Quote:

And why not use

Code:

using namespace std;

(I know it might be your way of writing codes, I just want to make sure I follow everything here.

I could have used the using declaration local to main (global namespace pollution is bad and should be avoided) yet it is as you say just a preference and how long does it take to type "std::"? When working with a large codebase it makes it explicit what you mean, as there could be code in different namespaces which have structures of the same name.

Quote:

And Is this the solutions to conio.h problem in Linux?

The problem is the author is using windows only functions, in my opinion this is wrong as he is meant to be teaching C++.

faizlo · 09-06-2008, 05:56 AM

dmail,

Thank You.

faizlo

graemef · 09-06-2008, 06:27 AM

Quote:

Originally Posted by faizlo

graemef, I have tried replacing \n with \r and I got the first line (asking about the direction) and nothing happens whenever I press n,e,s,w. but it quits when I use q.

faizlo

I meant add not replace I believe that within ncurses \n is move to the next line but keep the same column whilst \r is move to the first column. However, dmail's solution is much neater.