This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Is JavaScript’s Math broken?
Funny question, but why at 16.1 javascript become "crazy"? :)
Code :
var value1=16.1;
var value2=16.2;
console.log(value1 * 1000);
console.log(value2 * 1000);
Output :
16100.000000000002
16200
Why?
That's because javascript casts everything to a double internally. As a result, all calculations pick up some noise due to floating point inaccuracy: Floating point inaccuracy examples
One way to fix this issue, is to just round down to the nearest int after all intermediate calculations.
Answer Copy From Here
It's not a javascript problem, it's a problem related to any programming language using floating point numbers, see
Is floating point math broken?
for explanation of the root problem and for some useful workarounds too.
Related
This question already has answers here:
How to deal with floating point number precision in JavaScript?
(47 answers)
Closed last month.
I´ve come across this oddity when writing some JS code. It happens in both Chrome and Firefox:
10.04 + 0.01 = 10.049999999999999
Not sure if I´m just missing something obvious that causes this?
Right now I am handling it with rounding the number afterwards - Is there a better way to avoid this bug/feature?
This is a consequence of the way numbers are stored internally in IEEE 754 form.
To avoid this, use a BigDecimal library such as this one: https://www.npmjs.com/package/js-big-decimal
This question already has answers here:
Large numbers erroneously rounded in JavaScript
(6 answers)
Closed 5 years ago.
I'm new in developing javascript apps, i have a doubt about a behaviour that i'm going to try to explain.
If i execute:
Number(5555555555555555);
Result: 5555555555555555
But if i execute:
Number(55555555555555555);
Result: 55555555555555550
Anybody can explain to me what is the reason of this? Thanks!!
If you need to work with such big numbers I would suggest you use some of the big integer libraries such as this. The reason this happens as far as I know is the way processors and memory work. It's no related to some "bug" in JS.
Integers (numbers without a period or exponent notation) are accurate up to 15 digits. Javacript simply adds zeros to keep the number accurate in terms of its digit length.
Documentation
This question already has answers here:
Javascript float subtract
(6 answers)
How to deal with floating point number precision in JavaScript?
(47 answers)
Closed 6 years ago.
So I am having issues with numbers:
I have a item, with a price of 483.65. I want to multiply this by 7. Expected result should be:
3385.55
However, Javascript reds this as:
3385.5499999999997
The number in the database is stored as a Float.
Here are screenshots to explain the situation better:
What am I missing?
be careful with floating point math operations.
thats because of floating point standard used by js vm.
one trick I found to fix it without external libs is to multiple by 1k and than divid by 1k.
483.65 * 1000 * 7 / 1000
strange but always works.
This question already has answers here:
Why does floating-point arithmetic not give exact results when adding decimal fractions?
(31 answers)
Closed 8 years ago.
I'm learning Javascript at the moment and the particular lesson that I'm on right now is showing how to turn 1.075 into 7.5% for display purposes.
the math looks as follows:
(1.075 - 1) * 100
and this is displaying in the results as 7.499999999999996. Why in the world is it calculating like this in Javascript? Every calculator that I used to do the exact same math came up as 7.5, as it should. I didn't even need a calculator to realize something was odd, but I wanted to run the same numbers on as many calculators as I could just to reassure myself. I'm actually shocked that the guy doing the tutorials didn't say a single thing about that, other than how to fix it to display only 2 decimal places, because this just seems so odd. So what be going on? I'm crazy curious about what's going on here.
Thanks!
I want to apologize to everyone that was obviously very upset by my asking a duplicate question, and decided to downvote me for it. I would have been just as well searching for an answer, only I don't even know how I could have began to query for such a question.
To the people that answered, and linked me to another article answering my question; thank you very much, and I apologize for the duplicate :)
Some decimal numbers cannot be accurately stored as floating point numbers since they are periodic in binary. 1075/1000 is such a number.
http://floating-point-gui.de/
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Is JavaScript's Math broken?
I've some problems with javascript.
If I do this:
alert(6.000 * 1.050);
I expect 6.3, but I get 6.30000001
can anybody help me ? or explain why this happens?
Here you can simple use the method toFixed() in java-script
alert(parseFloat(6.000 * 1.050).toFixed(1));
They're called floats, and sometimes have a little bit of inaccuracy.
http://en.wikipedia.org/wiki/Floating_point#Accuracy_proble
Standard problem; decimals can't be stored with infinite precision in general, so most programming languages have data types that approximates them and show a rounded version. Problem is that multiplication or subtraction can cause the inaccuracies to show.
In the end, you'll just have to round probably.