Parsing numbers with a comma decimal separator in JavaScript

I used this function to check if a value is a number:

function isNumber(n) {
    return !isNaN(parseFloat(n)) && isFinite(n);
}

My program need to work with German values. We use a comma as the decimal separator instead of a dot, so this function doesn't work.

I tried to do this:

n.replace(",",".")

But it also doesn't seem to work. The exact function I tried to use is:

function isNumber(n) {
    n=n.replace(",",".");
    return !isNaN(parseFloat(n)) && isFinite(n);
}

The number looks like this 9.000,28 instead of the usual 9,000.28 if my statement wasn't clear enough.

You need to replace (remove) the dots first in the thousands separator, then take care of the decimal:

function isNumber(n) {
    'use strict';
    n = n.replace(/\./g, '').replace(',', '.');
    return !isNaN(parseFloat(n)) && isFinite(n);
}

var number = parseFloat(obj.value.replace(",",""));

You'll probably also want this to go the other way...

obj.value = number.toLocaleString('en-US', {minimumFractionDigits: 2});

I believe the best way of doing this is simply using the toLocaleString method. For instance, I live in Brazil, here we have comma as decimal separator. Then I can do:

var number = 10.01;
console.log(number)
// log: 10.01

console.log(number.toLocaleString("pt-BR"));
// log: 10,01