How do you round to 1 decimal place in Javascript?

Question

Can you round a number in javascript to 1 character after the decimal point (properly rounded)?

I tried the *10, round, /10 but it leaves two decimals at the end of

Answer 1

This seems to work reliably across anything I throw at it:

function round(val, multiplesOf) {
  var s = 1 / multiplesOf;
  var res = Math.ceil(val*s)/s;
  res = res < val ? res + multiplesOf: res;
  var afterZero = multiplesOf.toString().split(".")[1];
  return parseFloat(res.toFixed(afterZero ? afterZero.length : 0));
}

It rounds up, so you may need to modify it according to use case. This should work:

console.log(round(10.01, 1)); //outputs 11
console.log(round(10.01, 0.1)); //outputs 10.1