whether keep two decimal places can solve precision loss

Question

The classic precision loss case

0.3 - 0.1  // 0.19999999999999998

Howerver, if we only calculate number of two decimal places and use toFixed(2) , did it is hava a risk?

(0.3 - 0.1).toFixed(2)  // '0.20'

Answer 1

You can end up getting weird rounding behavior. Maybe don't use it for money

 console.log((0.3 - 0.005).toFixed(2))//should be .29 console.log(Math.round((0.3 - 0.005)*100)/100)//should be .3(0)

Answer 2

可以用big.js来解决，只有24.4kb