ES7: a simple and useful guide to master it

After exploring all the new features from ES6 (ES2015), installation, history and name pattern in this article, I will tell you about the releases of ES7 (ES2016). And if you are afraid that it will be as big as the first one, don't worry; it is much smaller.

TC39 (the Technical Committee that writes the spec) released ES7 in June 2016, and it came with two new features that will make your life a little bit easier. Let's see them:

ES2016

Tip: try to open the console of your browser and test these examples. Super cool!

Array.prototype.includes

We got used to looking for elements in an array with array.indexOf(el) !== -1, but now this is a thing of the past. We can look for them in a simpler way:

['a', 'b', 'c'].includes('b');      // true
['a', 'b', 'c'].includes('d');      // false
['a', 'b', 'c'].includes('c', 2);   // true
['a', 'b', 'c'].includes('c', 3);   // false
['a', 'b', 'c'].includes('c', 'g'); // true
['a', 'b', NaN].includes(NaN);      // true
# also a string
'a123b'.includes('123')             // true 

The syntax of this function is:

element.includes(searchElement[, fromIndex])

• searchElement — the element that you are looking for
• fromIndex — from which position the search will start. Default: 0

Exponentiation Operator (**)

This function returns the result of the mathematical expression baseⁿ, where n is the exponent. In Javascript the exponentiation symbol is ** and can be used like so:

base ** exponent

Some examples:

2 ** 3         // 8
3 ** 2         // 9
3 ** 0.5       // 1.7320508075688772
10 ** -1       // 0.1
NaN ** 2       // NaN

3 ** (2 ** 4)  // 43046721
(3 ** 2) ** 4  // 6561

And that's it. ES7 is simpler to learn. Now you master it ;)

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Thank you for the revision, Shawn McCarthy and Chris de Graaf.

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Flávio H. de Freitas is an Entrepreneur, Engineer, Tech lover, Dreamer and Traveler. Has worked as CTO in Brazil, Silicon Valley and Europe.