TRACE( exp );
A variable number of arguments used exactly in the same way as the run-time function printf uses them.
In the Debug environment, the TRACE macro output goes to afxDump. In the Release environment, it does nothing. This is a convenient way of generating debugging output that will appear only in the Debug version of your program.
int i = 1;
char sz[] = "one";
TRACE( "Integer = %d, String = %s\\n", i, sz );
// Output: 'Integer = 1, String = one'