ES2016

A breif quick and dirty run through for getting a taste of the ES2016 JavaScript

The additions of ES2016 are light

Array.protoype.includes

The array type now has an includes method built into it. This method searching through the array much like indexOf but instead of returning an index number, it will return a Boolean to the caller.

Examples

['a', 'b', 'c'].includes('c'); // => true

['a', 'b'].includes('c'); // => false

Comparing complex types Note here that these are EMPTY objects

[{}, {}].includes({}); // => false

const a = {};

[{}, a].includes(a); // => true

This is a simple check which passes because the variable a takes up the same memory in this case meaning it is comparable

You can also specify a point to start your search with a second parameter

['a', 'b', 'c', 'd'].includes('a', 1); // => false

Even though you can't compare NaN types so NaN !== NaN .includes uses the SameValueZero comparison algorithm where NaN is actually equivalent to itself.

[NaN].includes(NaN); // => true

And that's about it for the includes method.

Exponentiation Operator (**)

The exponentiation operator – or a ** b – is the syntactic equivalent to doing Math.pow(a, b). It’ll work similarly to the exponentiation operator in Python.

Examples

1 ** 2 === Math.pow(1, 2); // => true

Just like with any other operators, it’s possible to mix exponentiation with assignment, as show below.

let a = 2;
a **= 3; // equivalent to a = Math.pow(a, 3)
console.log(a); // => 8

Conclusion

So that about does it for ES2016 pretty simple and much smaller than ES2015 additions right?