The double asterisk ** operator in Javascript

DanielFebruary 18, 2023March 4, 2023

New day, a new discovery! Today I’ve learned there that Javascript has a double asterisk ** operator.

So, it’s perfectly valid to write:

const x = 2 ** 3
// x is 8, meaning 2 raised to a power of 3

const y = x ** 2
// x is 64, squared x

The double asterisk ** operator was introduced in ECMAScript 2016 and it’s also named the exponentiation operator.

Writing x ** y it’s the same as writing Math.pow(2, 3).

It works also with negative or fractional values:

const z = 7 ** -2 
// z is 0.02040816326530612, 1 / 49

const t = 4 ** 0.5 
// t is 2

And we also have the exponentiation assignment:

x **= y
// meaning x = x ** y

The support for the double asterisk is great, works everywhere except IE.

And speaking of lesser-known operators in Javascript, we also have a double tilde Js operator.