Issue with numbers

programming flash
1

Hey All,

I am having issues subtracting numbers – yes subtracting haha

Basically I add 0.99 + 0.99 + 0.99

I get: 2.97 - great!

Now when I subtract 0.99 one at a time (using AS) It goes like this:
2.97 - 0.99 = 1.98
1.98 - 0.99 = 0.99
0.99 - 0.99 = -2.22044604925031e-16

?? how did we get that number :slight_smile:

My code

total_price is defined as a number and starts at 0.00.

Eg: var total_price:Number = 0.00;

songs is an array that contains information about each song that is loaded - in the multi-level array number 5 represents the price of the song. Which on eash song is defaulted to 0.99.


function addItem(element){
    var track = substring(element, 27, 1);
    _root.total_price+=Number(songs[track][5]);
    _root.price.cost.text="$"+_root.total_price;
    }

function removeItem(element){
    var track = substring(element, 27, 1);
    _root.total_price-=Number(songs[track][5]);
    _root.price.cost.text="$"+_root.total_price;
    }

Anyone have any clue why I get such a random number such as “-2.22044604925031e-16”?

If I remove and add only 2 sets of 0.99 is comes out 0 - its only when I do more then 2 calculations.

Thanks for any advice!