59.99 + 10 = 69.99 is true as a general Math calculation.
but if we trace it with flash as bellow
trace(59.99 + 10 == 69.99)
it says false.
is the above condition is an exception?
That's how things are in most computer languages. The CPU is working with binary, and even at 64 bits it doesn't always match what decimal would give you.
Try this line to see that there is a tiny difference in the values:
trace((59.99 + 10)*100000000000000);
You can work around that by doing your own rounding:
trace(Math.round(100*(59.99 + 10))/100 == 69.99);
One would hope he managed to solve the problem himself in the SIX YEARS since this question was posted.
Very strange that the message only showed up today at 2:08pm for me..