For-loop in C++ using double breaking out one step early, boundary value not reached

Question

I have a simple C++ program compiled using gcc 4.2.4 on 32-bit Ubuntu 8.04. It has a for-loop in which a double variable is incremented from zero t

Answer 1

Generally, when you compare doubles, simple comparison is not good enough, and you should compare them "up to a precision". i.e. :

if ( fabs(double1-double2) < 0.0000001 ) {
  do-something
}

The problem occurs due to the representation of double variables.