std::cin skipped after for loop [duplicate] - c++

Question

I'm working through a text book for self study. I can do the while loop no problem, but I have no idea how to do the terminating character.
Here is what I have now:
#include "../../std_lib_facilities.h" // Supplied by book author
int main()
{
int ii = 0;
int yy = 0;
bool test = true;
cout << "Enter two ints" << endl;
while (test)
{
cin>>ii, cin>>yy;
// this if statement doesn't work
if (ii == '|' || yy == '|')
{
test = false;
}
// this if statement catches all bad input, even the terminating '|'
if (cin.fail())
{
cout << "bad input";
cin.clear();
cin.ignore();
continue;
}
else
cout << ii << yy << endl;
}
return 0;
}

Answer 1

Streams can be a little confusing if you're unfamiliar with them. It's a large topic that's just going to require more research. Here's an example that should work, to hopefully get you started.
int main(int argc, char* argv[])
{
bool test = true;
while ( test ) {
std::cout << "Enter two integers> ";
int x, y;
// if this fails, stream is bad.
// #note this will fail for any input which cannot be interpreted
// as an integer value.
if (std::cin >> x >> y) {
std::cout << x << " " << y << std::endl;
}
else {
// clear stream error state so we can read from it again.
std::cin.clear();
// check for terminating character; else unknown.
if (std::cin.get() == '|')
std::cout << "Terminator found, exiting." << std::endl;
else
std::cerr << "Error: bad input, exiting." << std::endl;
// in either case the loop terminates.
test = false;
}
}
return 0;
}
Hope this helps. Good luck.

Answer 2

Use the cin.peek() function as follows, before you input the two numbers:
c=(cin >> ws).peek();
if(c=='|')
{
cout<<"exiting";return 1;
}
Note: (cin>>ws) is to get rid of leading whitespaces. Also, c is of type char.
The complete code now looks like this:
int main()
{
int ii = 0;
int yy = 0;
bool test = true;
cout << "Enter two ints" << endl;
while (test)
{
char c;
c=(cin >> ws).peek();
if(c=='|')
{
cout<<"exiting";return 1;
}
cin>>ii, cin>>yy;
if (cin.fail())
{
cout << "bad input";
cin.clear();
cin.ignore();
continue;
}
else
cout << ii << yy << endl;
}
return 0;
}