Weird floats in JS?

Question

Hello, coders! I've got possibly very stupid question about JavaScript that most certainly have an answer somewhere out there. Here goes...

Suppose, I have two vars:
i = 6 and di = 0.2
Every time a button is pressed runs following bit of code:
i = i + di;
As a result I get series of numbers:
6, 6.2, 6.4, 6.6000000000000005, 6.800000000000001, etc...

Why is this happening? Can I somehow limit my floats to one decimal? Or do I have to round var 'i' each iteration?

I know, it would probably be easier to give up floats altogether in this particular case (by multiplying by 10), but I'd like to understand what's going on at least.

Answer 1

found this explanation

https://docs.python.org/release/2.5.1/tut/node16.html

Answer 2

you can use toPrecision

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Number/toPrecision

Answer 3

💪

Answer 4

deals with how computers inaccurately represent floating point numbers. its not your fault. you can google more on this subject

Answer 5

Oh! Thanks a lot! =) It was very confusing for a moment there, but I see it now.
It's just that I never quite had this problem before in C++, although to be fair it probably has to do with the fact that there you can easily specify how many decimals you want to print. So, I suppose I'd have to find a little workaround to achieve similar effect.

Answer 6

Much appreciated, Burey =) I'll get right on it.