Merge branch 'master' of https://github.com/reactjs/reactjs.org into sync-7b217c70

Author: reactjs-translation-bot

content/community/conferences.md

@@ -22,6 +22,11 @@ May 25, 2019 in Yerevan, Armenia
 
 [Website](https://reactconf.am/) - [Twitter](https://twitter.com/ReactConfAM) - [Facebook](https://www.facebook.com/reactconf.am/) - [YouTube](https://www.youtube.com/c/JavaScriptConferenceArmenia) - [CFP](http://bit.ly/speakReact)
 
+### ReactNext 2019 {#react-next-2019}
+June 11, 2019. Tel Aviv, Israel
+
+[Website](https://react-next.com) - [Twitter](https://twitter.com/ReactNext) - [Videos](https://www.youtube.com/channel/UC3BT8hh3yTTYxbLQy_wbk2w)
+
 ### React Norway 2019 {#react-norway-2019}
 June 12, 2019. Larvik, Norway
 
@@ -57,6 +62,11 @@ September 13th, 2019. New York, USA
 
 [Website](https://reactnewyork.com/) - [Twitter](https://twitter.com/reactnewyork)
 
+### React Live 2019 {#react-live-2019}
+September 13th, 2019. Amsterdam, The Netherlands
+
+[Website](https://www.reactlive.nl/) - [Twitter](https://twitter.com/reactlivenl)
+
 ### React Boston 2019 {#react-boston-2019}
 September 21-22, 2019 in Boston, Massachusetts USA
 

content/community/meetups.md

@@ -138,6 +138,7 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 * [Portland, OR - ReactJS](https://www.meetup.com/Portland-ReactJS/)
 * [Provo, UT - ReactJS](https://www.meetup.com/ReactJS-Utah/)
 * [Sacramento, CA - ReactJS](https://www.meetup.com/Sacramento-ReactJS-Meetup/)
+* [San Francisco - Real World React](https://www.meetup.com/Real-World-React)
 * [San Francisco - ReactJS](https://www.meetup.com/ReactJS-San-Francisco/)
 * [San Francisco, CA - React Native](https://www.meetup.com/React-Native-San-Francisco/)
 * [San Ramon, CA - TriValley Coders](https://www.meetup.com/trivalleycoders/)

content/docs/hooks-faq.md

@@ -844,9 +844,9 @@ Traditionally, performance concerns around inline functions in React have been r
     }, [a, b]);
     ```
 
-* The [`useMemo` Hook](/docs/hooks-faq.html#how-to-memoize-calculations) makes it easier to control when individual children update, reducing the need for pure components.
+* The [`useMemo`](/docs/hooks-faq.html#how-to-memoize-calculations) Hook makes it easier to control when individual children update, reducing the need for pure components.
 
-* Finally, the `useReducer` Hook reduces the need to pass callbacks deeply, as explained below.
+* Finally, the [`useReducer`](/docs/hooks-reference.html#usereducer) Hook reduces the need to pass callbacks deeply, as explained below.
 
 ### How to avoid passing callbacks down? {#how-to-avoid-passing-callbacks-down}
 

content/docs/hooks-intro.md

@@ -81,7 +81,7 @@ We'll discuss this more in [Using the Effect Hook](/docs/hooks-effect.html#tip-u
 
 In addition to making code reuse and code organization more difficult, we've found that classes can be a large barrier to learning React. You have to understand how `this` works in JavaScript, which is very different from how it works in most languages. You have to remember to bind the event handlers. Without unstable [syntax proposals](https://babeljs.io/docs/en/babel-plugin-transform-class-properties/), the code is very verbose. People can understand props, state, and top-down data flow perfectly well but still struggle with classes. The distinction between function and class components in React and when to use each one leads to disagreements even between experienced React developers.
 
-Additionally, React has been out for about five years, and we want to make sure it stays relevant in the next five years. As [Svelte](https://svelte.technology/), [Angular](https://angular.io/), [Glimmer](https://glimmerjs.com/), and others show, [ahead-of-time compilation](https://en.wikipedia.org/wiki/Ahead-of-time_compilation) of components has a lot of future potential. Especially if it's not limited to templates. Recently, we've been experimenting with [component folding](https://github.com/facebook/react/issues/7323) using [Prepack](https://prepack.io/), and we've seen promising early results. However, we found that class components can encourage unintentional patterns that make these optimizations fall back to a slower path. Classes present issues for today's tools, too. For example, classes don't minify very well, and they make hot reloading flaky and unreliable. We want to present an API that makes it more likely for code to stay on the optimizable path.
+Additionally, React has been out for about five years, and we want to make sure it stays relevant in the next five years. As [Svelte](https://svelte.dev/), [Angular](https://angular.io/), [Glimmer](https://glimmerjs.com/), and others show, [ahead-of-time compilation](https://en.wikipedia.org/wiki/Ahead-of-time_compilation) of components has a lot of future potential. Especially if it's not limited to templates. Recently, we've been experimenting with [component folding](https://github.com/facebook/react/issues/7323) using [Prepack](https://prepack.io/), and we've seen promising early results. However, we found that class components can encourage unintentional patterns that make these optimizations fall back to a slower path. Classes present issues for today's tools, too. For example, classes don't minify very well, and they make hot reloading flaky and unreliable. We want to present an API that makes it more likely for code to stay on the optimizable path.
 
 To solve these problems, **Hooks let you use more of React's features without classes.** Conceptually, React components have always been closer to functions. Hooks embrace functions, but without sacrificing the practical spirit of React. Hooks provide access to imperative escape hatches and don't require you to learn complex functional or reactive programming techniques.
 

content/docs/optimizing-performance.md

@@ -153,7 +153,7 @@ new webpack.DefinePlugin({
 new webpack.optimize.UglifyJsPlugin()
 ```
 
-You can learn more about this in [webpack documentation](https://webpack.js.org/guides/production-build/).
+You can learn more about this in [webpack documentation](https://webpack.js.org/guides/production/).
 
 Remember that you only need to do this for production builds. You shouldn't apply `UglifyJsPlugin` or `DefinePlugin` with `'production'` value in development because they will hide useful React warnings, and make the builds much slower.
 

content/docs/reference-javascript-environment-requirements.md

@@ -11,8 +11,8 @@ React 16 depends on the collection types [Map](https://developer.mozilla.org/en-
 A polyfilled environment for React 16 using core-js to support older browsers might look like:
 
 ```js
-import 'core-js/es6/map';
-import 'core-js/es6/set';
+import 'core-js/es/map';
+import 'core-js/es/set';
 
 import React from 'react';
 import ReactDOM from 'react-dom';

content/tutorial/tutorial.md

@@ -523,7 +523,7 @@ Note how in `handleClick`, we call `.slice()` to create a copy of the `squares`
 
 ### Why Immutability Is Important {#why-immutability-is-important}
 
-In the previous code example, we suggested that you use the `.slice()` operator to create a copy of the `squares` array to modify instead of modifying the existing array. We'll now discuss immutability and why immutability is important to learn.
+In the previous code example, we suggested that you use the `.slice()` method to create a copy of the `squares` array to modify instead of modifying the existing array. We'll now discuss immutability and why immutability is important to learn.
 
 There are generally two approaches to changing data. The first approach is to *mutate* the data by directly changing the data's values. The second approach is to replace the data with a new copy which has the desired changes.