Ruby | 2 float number multiple not giving the exact value

Question

I have 2 float number and I try to get the multiple. But in the console it does not get the correct one. I do not know maybe there is a leak ?

{"price"=>"0.049391", "size"=>"0.001"}

When I multiple them console shows;

************
0.049391
************
0.001
************
4.9390999999999995e-05
************

Then when I push this data to array and in front end when I console.log

I get;

0.000049390999999999995

Why it is not 0.0000493901 ?

The latter is a more precise representation of the same number. Why would you want the less precise scientific notation? — Sergio Tulentsev, Dec 28 '17 at 08:11
"Why it is not 0.0000493901" - ah, __now__ I can cast that close vote :) — Sergio Tulentsev, Dec 28 '17 at 08:12
But the calculation is not true, I do not need that precise number. I would like to get what google calculator gives :) which is 0.0000493901 — Shalafister's, Dec 28 '17 at 08:12
Somebody, please dup-close this, I wasted my vote: https://stackoverflow.com/questions/588004/is-floating-point-math-broken — Sergio Tulentsev, Dec 28 '17 at 08:12

score 1 · Answer 1 · answered Dec 28 '17 at 08:12

1

4.9390999999999995e-05 and 0.000049390999999999995 are the same number. e-05 is nothing more than notation for "move the decimal place five spots to the left".

answered Dec 28 '17 at 08:12

Derek Kraan

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The OP wants 0.000049391, not 0.000049390999999999995 – Stefan Dec 28 '17 at 12:00
Ah, right you are. Well in that case OP is SOL, because this is just a quirk of floating point precision, and the answer has been rightly marked as a duplicate. – Derek Kraan Dec 29 '17 at 10:00

Ruby | 2 float number multiple not giving the exact value

1 Answers1