Do you care about JS Math problem?

Question

You probably know that JS math is inaccurate - for example, alert(0.1 + 0.2) outputs 0.30000000000000004. So, my qustion is: when you are counting with an number typed by client, do you care about this? If yes, how?

Answer 1

Anton Böhler Ole113 Thank you 😊

Answer 2

It really shouldnt matter unless you’re doing super exact calculations. If you need a longer float you can use some of the Node.js BigInt librarys.

Answer 3

in general a computer will always think that
0.1 + 0.2 == 0.3
is false
(it's not only js😅)
it's because of the way floats are stored...

to go around this you can do sth like this:
0.3 - (0.2 + 0.1) < 0.00001
or
round the two numbers your testing

Answer 4

The weird of floating point 😂😂😂

There are some libraries to solve it.

https://github.com/MikeMcl/big.js/wiki

Even a BigInt native type:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt

In progress a ECMA proposal to establish a standard, maybe implemented on ES2020, ES2021

https://github.com/tc39/proposal-decimal