works, although with the interval expressed in floating point, you have to be careful.
is safer, since the increment is an integer. If you are plugging the resulting value of h into some expression within the for loop there will be no problems. But if you are comparing h to some other value computed in the for loop, a la
if h == [some computed value]
you of course have to beware of floating point comparisons that might disagree in the 16th decimal place and give you an unwanted answer.