CODEWITHSUNDEEP
javascriptreactjsbignumparsefloat
007DevilsWorkshop
007DevilsWorkshop

Reputation: 33

Parse Float string to number rounding off javascript

I have the string "9999999999999.99999" which I covert using Parse Float. But it changes the value to 10000000000000 , is there anyway I can have the get the number same without rounding off?

The input is string and out must be number not string. ex: ParseFloat("9999999999999.99999") = 9999999999999.99999 . So the output should not be string instead number

Upvotes: 0

Views: 487

Answers (2)

Terry Lennox
Terry Lennox

Reputation: 30675

You could have a look at decimal.js, this allows an arbitrary level of precision to be specified.

const x = new Decimal("9999999999999.99999");
console.log('x:', x.toString())

// Manipulate x
console.log('x * 2:', x.mul(2).toString())
console.log('x / 2:', x.div(2).toString())
<script src="https://cdnjs.cloudflare.com/ajax/libs/decimal.js/9.0.0/decimal.min.js" integrity="sha512-zPQm8HS4Phjo9pUbbk+HPH3rSWu5H03NFvBpPf6D9EU2xasj0ZxhYAc/lvv/HVDWMSE1Autj19i6nZOfiVQbFQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>

Upvotes: 0

Noa
Noa

Reputation: 1216

Well there is a bit limit to what numbers Javascript can handle (until we get BigInt64 or if you use a library like decimal.js). So since it cannot handle more decimals it just truncates at a point. If you would make a bigger number you would see less decimals. If this then leads to the number being "exacly" 9999999999999.99 in your case javascript will correctly show it as 9999999999999.99 and not 9999999999999.99999 since we only have Number and not float, decimal, int, etc.

parseFloat(9999999999999.99999);
// 9999999999999.99
parseFloat(9999999999999.9999);
// 9999999999999.99
parseFloat(9999999999999.999);
// 9999999999999.998
parseFloat(9999999999999.99);
// 9999999999999.99

Edit: actually it seem to round and not drop.

I hope that explains things.

Upvotes: 1

Related Questions