<commit_before>---
title: Opera 34 released
authors:
- mathias-bynens
intro: 'Opera 34 (based on Chromium 47) for [Mac, Windows, and Linux](http://www.opera.com/computer) is out! To find out what’s new for users, see our [Desktop](http://blogs.opera.com/desktop/2015/12/opera-34-technology-help/) blog. Here’s what it means for web developers.'
tags:
- html
- css
- javascript
- opera
license: cc-by-3.0
---

Opera 34 (based on Chromium 47) for [Mac, Windows, and Linux](http://www.opera.com/computer) is out! To find out what’s new for users, see [our Desktop blog](http://blogs.opera.com/desktop/2015/12/opera-34-technology-help/). Here’s what it means for web developers.

## `Array.prototype.includes`

ES2016 (previously known as “ES7”) features [a new array method named `includes`](https://tc39.github.io/Array.prototype.includes/) that determines whether an array includes a given element.

	// Good ol’ ES5:
	var isIncluded = someArray.indexOf(element) != -1;
	// Shiny new ES6:
	const isIncluded = someArray.includes(element);

Compared to the old-school `indexOf` approach, `includes` handles `NaN` more elegantly:

	var array = [NaN];
	array.indexOf(NaN) === -1;
	// → false<commit_msg>Fix typos<commit_after>---
title: Opera 34 released
authors:
- mathias-bynens
intro: 'Opera 34 (based on Chromium 47) for [Mac, Windows, and Linux](http://www.opera.com/computer) is out! To find out what’s new for users, see our [Desktop](http://blogs.opera.com/desktop/2015/12/opera-34-technology-help/) blog. Here’s what it means for web developers.'
tags:
- html
- css
- javascript
- opera
license: cc-by-3.0
---

Opera 34 (based on Chromium 47) for [Mac, Windows, and Linux](http://www.opera.com/computer) is out! To find out what’s new for users, see [our Desktop blog](http://blogs.opera.com/desktop/2015/12/opera-34-technology-help/). Here’s what it means for web developers.

## `Array.prototype.includes`

ES2016 (previously known as “ES7”) features [a new array method named `includes`](https://tc39.github.io/Array.prototype.includes/) that determines whether an array includes a given element.

	// Good ol’ ES5:
	var isIncluded = someArray.indexOf(element) != -1;
	// Shiny new ES2016:
	const isIncluded = someArray.includes(element);

Compared to the old-school `indexOf` approach, `includes` handles `NaN` more elegantly:

	var array = [NaN];
	array.indexOf(NaN) != -1;
	// → false
{'fraction_non_alphanumeric': 0.14076858813700918, 'fraction_numerical': 0.03383458646616541, 'mean_word_length': 4.117521367521367, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 3, 'https://': 2, 'lorem ipsum': 0, 'www.': 4, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '7135385', 'n_tokens_mistral': 862, 'n_tokens_neox': 774, 'n_words': 260}