Rounding up to two decimal place in javascript eg 4.9995 to 4.99 in mathematical way in js

Question

How can I convert decimal number to 2 decimal place number? Example: I want to connvert 4.995 to 4.99 but javascript is returning 5.00.

var price=4.995;
var rounded_price=price.toFixed(2);
console.log(rounded_price);

console.log(rounded_price); is returning me 5 however I want to have 4.99. Please assist — Er Gagandeep Sethi, Jan 15 '17 at 15:19
Possible duplicate of [JavaScript math, round to two decimal places](http://stackoverflow.com/questions/15762768/javascript-math-round-to-two-decimal-places) — Aurora0001, Jan 15 '17 at 15:20
Rounded `4.995` is `5.00`. No error here. I bet you either don't know what round does or don't want to round. — , Jan 15 '17 at 15:21
that would be wrong way.. is there no way converting 4.999966 to 2 decimal place number?????? — Er Gagandeep Sethi, Jan 15 '17 at 15:24
There's no fixed decimal numbers in JS, even `toFixed()` returns a string. — Teemu, Jan 15 '17 at 15:25
ok.. I was curious to know this in mathematical way in js.. otherwise other tricks I have already tried :P — Er Gagandeep Sethi, Jan 15 '17 at 15:27
Upvoted question... This is a valid point. `toFixed(2)` **Should** return 4.99 (as in currency for example), but it returns 5.00 (a different monetary value) which is wrong. — allnodcoms, Jan 15 '17 at 15:29

score 4 · Accepted Answer · answered Jan 15 '17 at 15:23

4

I wouldn't call it rounding but you can achieve it by:

function trim2Dec(n) {
  return Math.floor(n * 100) / 100;
}

alert(trim2Dec(4.995));

answered Jan 15 '17 at 15:23

user2832344

264
2
7

score 0 · Answer 2 · answered Jan 15 '17 at 15:30

0

You can use regex for this as the following:

alert("4.995".replace(/(\d+(\.\d{1,2})?)\d*/, "$1"))

answered Jan 15 '17 at 15:30

Ghasan غسان

5,577
4
33
44

1

To (mis)Quote: "If you have a problem, and RegEx is your answer - you now have two problems". ;o) – allnodcoms Jan 15 '17 at 15:41
@allnodcoms If you find yourself having to invent the wheel each time you program, then know you are using JavaScript. In any proper language, this method will be supported by a standard library specification. However, in JavaScript, everyone does what they think is best. – Ghasan غسان Jan 15 '17 at 15:56
The number of ways to solve a problem in javascript = n + 1, where n = The number of ways to solve a problem in javascript... – allnodcoms Jan 15 '17 at 16:03

Arnab Biswas · Answer 3 · 2017-01-15T16:18:55.473

0

This is Pretty simple check out this code

var price=4.995;
var price1=4.985;
var rounded_price=(Math.round(price*100)/100);
var rounded_price1=(Math.round(price1*100)/100);
console.log("price : "+rounded_price+"       price1 : "+rounded_price1);

here at first i am multiplying the price and then i have divided it with 100..just as we do to find the percentage of any number.

edited Jan 15 '17 at 16:18

answered Jan 15 '17 at 15:34

Arnab Biswas

9
5

This is very wrong. If you have a number like `4.015`, then you will get `4`! – Ghasan غسان Jan 15 '17 at 16:03
corrected..If you remove that -1 then the code will work fine..but you can not get exact result of 4.991 to 0.999 that will give you a result of 5 becuase its basically crossed the range – Arnab Biswas Jan 15 '17 at 16:18

Rounding up to two decimal place in javascript eg 4.9995 to 4.99 in mathematical way in js

3 Answers3