Error in formula using arithmetic operations with float

[cberdila]

Calculating 2.3 + 2.4 returns 4.699999999999999 instead of 4.7

About floating-point arithmetic operations go to:
http://floating-point-gui.de/
http://www.w3schools.com/js/js_numbers.asp

Steps to reproduce (on the demo web of calx2 jquery):

1. go to http://prototype.xsanisty.com/calx2/
2. introduce 2.3 + 2.4 in the formula textbox
3. the result shown 4.699999999999999 (the expected result 4.7)

Steps to reproduce (in JavaScript code):
calc.calx ('calculate', "2.3 + 2.4") // returns 4.699999999999999 (instead of 4.7)

I personally use it in a validation and I can not use it with the Excel ROUND function because the formulas are created by the users.
e.g. IF (2.3 + 2.4 = 4.7, "correct", "incorrect") // returns "incorrect" (instead of "correct")

[ikhsan017]

I think it is the nature way dealing with floating point on most language, the only way to fix this is improve the comparator formula to deal with floating point comparison

https://github.com/xsanisty/jquery-calx/blob/master/jquery-calx-2.2.7.js#L9347-L9371