Format INR currency using JavaScript

Update (September 2020): There is a better way of doing this and I have covered it here.

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"
		// "1,234,567.8"
	.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 RegExps, 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.

Format Regex

(Image generated using Regulex)