Javascript: formatting a rounded number to N decimals

Question

in JavaScript, the typical way to round a number to N decimal places is something like:

function roundNumber(num, dec) {
  return Math.round(num * Math.pow(10, dec)) / Math.pow(10, dec);
}

However this approach will round to a maximum of N decimal places while I want to always round to N decimal places. For example "2.0" would be rounded to "2".

Any ideas?

Answer 1

I think that there is a more simple approach to all given here, and is the method Number.toFixed() already implemented in JavaScript.

simply write:

var myNumber = 2;

myNumber.toFixed(2); //returns "2.00"
myNumber.toFixed(1); //returns "2.0"

etc...