math - Is the double asterisk ** a valid JavaScript operator?

Question

I solved a kata on CodeWars and was looking through some of the other solutions when I came across the double asterisk to signify to the power of. I have done some research and can see that this is a valid operator in python but can see nothing about it in JavaScript documentation.

var findNb = m =>
{
  var n = Math.floor((4*m)**.25);
  var sum = x => (x*(x+1)/2)**2;
  return sum(n) == m ? n : -1;
}

Yet when I run this solution on CodeWars, it seems to work. I am wondering if this is new in ES6, although I have found nothing about it.

Answer 1

Yes. ** is the exponentiation operator and is the equivalent of Math.pow.

It was introduced in ECMAScript 2016 (ES7).

For details, see the proposal and this chapter of Exploring ES2016.