Why isn't string resetting inside the loop? - c++

Question

I'm making a small desk cost program for a class. I wanted to include a loop into it. But every time I get to the end of the program and loop it back to the beginning, it skips the part where I ask for the customers name and leaves it blank. Any idea how to fix it?
Here's my code:
#include <iostream> // needed for Cin and Cout
#include <string> // needed for the String class
#include <math.h> // math functions
#include <stdlib.h>
using namespace std;
#define baseCost 200.00
#define drawerPrice 30.00
int main(void)
{
while(true)
{
string cname;
char ch;
cout << "What is your name?\n";
getline(cin, cname);
cout << cname;
cout << "\nWould you like to do another? (y/n)\n";
cin >> ch;
if (ch == 'y' || ch == 'Y')
continue;
else
exit(1);
}
return 0;
}

Answer 1

The problem is that you need to call cin.ignore() after your prompt for exit. When you use cin to get the 'ch' variable, a newline character is still stored in the input buffer. Call cin.ignore(), to ignore that character.
If you don't, you'll notice that the program prints a newline as the name on the second loop.
You could also make the 'ch' variable a string like 'cname' and use getline instead of cin. Then you wouldn't have to issue the cin.ignore() call.
#include <iostream> // needed for Cin and Cout
#include <string> // needed for the String class
#include <math.h> // math functions
#include <stdlib.h>
using namespace std;
#define baseCost 200.00
#define drawerPrice 30.00
int main()
{
while(true)
{
string cname;
char ch;
cout << "What is your name?\n";
getline(cin, cname);
cout << cname;
cout << "\nWould you like to do another? (y/n)\n";
cin >> ch;
// Slightly cleaner
if (ch != 'y' && ch != 'Y')
exit(1);
cin.ignore();
/*
if (ch == 'y' || ch == 'Y')
continue;
else
exit(1);
*/
}
return 0;
}