Javascript toFixed is not a function

Question

Hi the problem is following:

I define:

var total = 0;

function add(a){
  total+=a;
  var float_num = total.toFixed(2);
  return float_num;
}

The JS give me an error said Uncaught TypeError total.toFixed is not a function

I don't get it. the total I declare is not a number type?

Answer 1

I think the easiest way to prevent the error from happening is to always parse the parameter as number:

var total = 0;
function add(a){
  total+=a;
  var float_num = Number(total).toFixed(2);
  return float_num;
}