Strange result in simple math addition in JavaScript

Question

I have the following simple math operation.

var a = 1.12345678 + 1;
console.log(a);

which results in

2.1234567799999997

why?

I expect the result to be

2.12345678

read this http://stackoverflow.com/questions/5037839/avoiding-problems-with-javascripts-weird-decimal-calculations — Paul Fitzgerald, Dec 17 '15 at 23:26
Possible duplicate of [How to deal with floating point number precision in JavaScript?](http://stackoverflow.com/questions/1458633/how-to-deal-with-floating-point-number-precision-in-javascript) — Alex, Dec 17 '15 at 23:28

score 0 · Answer 1 · answered Dec 17 '15 at 23:28

0

I would just recommend using +a.toFixed(8) JavaScript uses floating point precision, which is never 100% accurate

answered Dec 17 '15 at 23:28

Scott Schwalbe

Not "never", only for those values it can't represent exactly. – RobG Dec 18 '15 at 01:21

score 0 · Answer 2 · answered Dec 17 '15 at 23:28

0

Simple solution:

Math.round(( OPERATION ) * 1e12) / 1e12

Supports all browsers. toFixed() causes strange things to happen on IE.

answered Dec 17 '15 at 23:28

Jerrybibo

2 Answers2