Javascript multiplication is not working properly for some numbers

Question

I have got a strange behavior in JavaScript multiplication.I was trying to multiply the number with 100. Eg:

    > 9.5*100
    > 950
    > 9.95*100
    > 994.9999999999999
    > 9.995*100
    > 999.4999999999999
    > 9.9995*100
    > 999.9499999999999
    > 9.99995*100
    > 999.995
    > 9.999995*100
    > 999.9995
    > 9.9999995*100
    > 999.9999499999999
    > 9.99999995*100
    > 999.9999949999999
    > 9.999999995*100
    > 999.9999995
    > 9.9999999995*100
    > 999.99999995
    > 9.99999999995*100
    > 999.999999995
    > 9.999999999995*100
    > 999.9999999995
    > 9.9999999999995*100
    > 999.9999999999501
    > 9.99999999999995*100
    > 999.999999999995
    > 9.999999999999995*100
    > 999.9999999999994

I just want the numbers to be multiplied like this

9.95*100
995.0 or 995
9.995*100
999.5
9.9995*100
999.95
9.9999995*100
999.99995

and NOT like this

> 9.995*100
> 999.4999999999999
> 9.9995*100
> 999.9499999999999
> 9.9999995*100
> 999.9999499999999

Is there any other method to multiply floating point Numbers?

If you multiply only by 100, maybe consider to turn the number into string then move the dot to it's right location and then convert it again to number — Ziki, Nov 09 '15 at 06:31
`b = (9.95).toString().split('.'); b[0]*100+b[1]*(100/(Math.pow(10,b[1].length)));` Most worst solution but works :P — Minato, Nov 09 '15 at 06:40

score 5 · Accepted Answer · answered Nov 09 '15 at 06:42

5

var factor = 100;
var number = 9.95;
var b = number.toString().split('.'); 
var answer = b[0]*factor+b[1]*(factor/(Math.pow(10,b[1].length)));

This is among the most worst solutions but works :P

answered Nov 09 '15 at 06:42

Minato

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It works! Thank you :-) – Able Johnson Nov 09 '15 at 07:06

Javascript multiplication is not working properly for some numbers

1 Answers1