cerr and clog

The cerr and clog streams direct output to standard error. cerr provides unbuffered output, while clog provides buffered output. The following example checks for a division by zero condition. If one occurs, a message is sent to standard error.

/**
 ** Check for a division by zero condition.
 ** If one occurs, a message is sent to standard error.
 **/

#include <iostream.h>
void main()
{
      double val1, val2;
      cout << "Divide Two Values" << endl;
      cout << "Enter two numeric values: " << endl;
      cin >> val1 >> val2;
      if (val2 == 0 )
      {
             cerr << "The second value must be non-zero" << endl;
      } else
             cout << "The answer is " << val1 / val2 << endl;
}