JavaScript is returning a repeating decimal

Asked Oct 23 '20 at 07:19

Active Oct 23 '20 at 07:23

Viewed 23 times

This array reduce line is the code I use to get a total.

let arr = [{c:25,q:1},{c:23.99,q:1},{c:32,q:1}];

let chg = arr.reduce((tot,b) => {return tot+b.c*b.q;},0);

I attempt to convert it to cents as per stripe with this code.

parseFloat(chg.toFixed(2)) * 100

And I get this! 8098.999999999999

WTF ‍♂️

I provided an example.

let arr = [{c:25,q:1},{c:23.99,q:1},{c:32,q:1}];


let chg = arr.reduce((tot,b) => {return tot+b.c*b.q;},0);

console.log(chg);
console.log(parseFloat(chg.toFixed(2)));
console.log(chg.toFixed(2))

console.log(parseFloat(chg.toFixed(2))*100)
console.log(parseFloat("80.99")*100)
console.log((80.99)*100)

Why is JavaScript returning a repeating decimal??

asked Oct 23 '20 at 07:19

D'andre Gregory

It's a floating point rounding error, see: https://floating-point-gui.de – hackape Oct 23 '20 at 07:22
https://stackoverflow.com/questions/1458633/how-to-deal-with-floating-point-number-precision-in-javascript – malarres Oct 23 '20 at 07:23

JavaScript is returning a repeating decimal

0 Answers0