Es2016

List of Changes

Just two changes:

1. Array.prototype.includes
2. Exponentiation Operator

Array.prototype.includes()

With ES6 and lower, to check if an array contained an element you had to use indexOf, which checks the index in the array, and returns -1 if the element is not there.

Since -1 is evaluated as a true value, you could not do for example

if (![1,2].indexOf(3)) {
  console.log('Not found')
}

With this feature introduced in ES2016 we can do

if (![1,2].includes(3)) {
  console.log('Not found')
}

Exponentiation Operator **

The exponentiation operator ** is the equivalent of Math.pow(), but brought into the language instead of being a library function.

Math.pow(4, 2) == 4 ** 2