Format INR currency in JavaScript

Formatting a number in JavaScript can be as simple as toLocaleString(), but while working on a side project, I came across a scenario where neither toLocaleString() nor toFixed() was enough.

I wanted the numbers to be in XX,XX,XXX.XX format. So, I tried bunch of different methods.

(254.4).toLocaleString() // "254.4"
(1234567.8).toLocalString() // "1,234,567.8"
(1234567.8).toFixed(2) // "1234567.80"  Number((1234567.8).toFixed(2)).toLocaleString() // "1,234,567.8"

As you can see that none of the methods worked as per my requirements.

After some googling and tinkering around with RegExp(s), I finally found a solution.

(1234567.8).toFixed(2).replace(/(\d)(?=(\d{2})+\d\.)/g, '$1,') // "12,34,567.80"

The above solution works flawlessly as per my requirements. Basically the regex looks for a digit which is followed by digits (in groups of two) followed by a digit and a decimal point.

Image Generated from http://jex.im/regulex

This article first appeared on vkbansal.me