Java Script parseFloat() unexpected decimal places-CodePudding

Why when I am cast this string "2019275.159999999916180968" to number, or when used parseFloat(str). I'm always get result "2019275.16". Why it remove extra decimal places that provided in the string? And how can i keep number of decimal places, without rounding it to 2 decimal places in this case?

Amount of decimal places in the string is dynamical.

CodePudding user response：

You can use toFixed() method after parseFloat() otherwise it will return least precision equivalent to internal representation

parseFloat("2019275.159999999916180968").toFixed(18)

CodePudding user response：

It might be worth investigating a library like decimal.js to help with this. e.g.:

Decimal.set({ precision: 24 }); // The default of 20 is not big enough for the number below so you may need to adjust this

let a = new Decimal('2019275.159999999912345');
a = a.plus(1);

let b = new Decimal('2019275.159999999912345').plus(1);
let c = Decimal.add('2019275.159999999912345', 1);

console.log(a, b, c);

<script src="https://cdnjs.cloudflare.com/ajax/libs/decimal.js/9.0.0/decimal.min.js"></script>