Refactor: Switch to let & const from var in JS, JSX, TS & TSX code-blocks

docs/_integration-with-existing-apps-java.md

@@ -178,7 +178,7 @@ const HelloWorld = () => {
     </View>
   );
 };
-var styles = StyleSheet.create({
+const styles = StyleSheet.create({
   container: {
     flex: 1,
     justifyContent: 'center',

docs/_integration-with-existing-apps-kotlin.md

@@ -178,7 +178,7 @@ const HelloWorld = () => {
     </View>
   );
 };
-var styles = StyleSheet.create({
+const styles = StyleSheet.create({
   container: {
     flex: 1,
     justifyContent: 'center',

docs/building-for-tv.md

@@ -35,8 +35,8 @@ TV devices support has been implemented with the intention of making existing Re
 - _JavaScript layer_: Support for Android TV has been added to `Platform.android.js`. You can check whether code is running on Android TV by doing
 
 ```js
-var Platform = require('Platform');
-var running_on_android_tv = Platform.isTV;
+const Platform = require('Platform');
+const running_on_android_tv = Platform.isTV;
 ```
 
 ## Code changes
@@ -50,7 +50,7 @@ var running_on_android_tv = Platform.isTV;
 - _TV remote/keyboard input_: A new native class, `ReactAndroidTVRootViewHelper`, sets up key events handlers for TV remote events. When TV remote events occur, this class fires a JS event. This event will be picked up by instances of the `TVEventHandler` JavaScript object. Application code that needs to implement custom handling of TV remote events can create an instance of `TVEventHandler` and listen for these events, as in the following code:
 
 ```tsx
-var TVEventHandler = require('TVEventHandler');
+const TVEventHandler = require('TVEventHandler');
 
 class Game2048 extends React.Component {
   _tvEventHandler: any;
@@ -113,12 +113,12 @@ class Game2048 extends React.Component {
 - _JavaScript layer_: Support for Apple TV has been added to `Platform.ios.js`. You can check whether code is running on AppleTV by doing
 
 ```tsx
-var Platform = require('Platform');
-var running_on_tv = Platform.isTV;
+const Platform = require('Platform');
+const running_on_tv = Platform.isTV;
 
 // If you want to be more specific and only detect devices running tvOS
 // (but no Android TV devices) you can use:
-var running_on_apple_tv = Platform.isTVOS;
+const running_on_apple_tv = Platform.isTVOS;
 ```
 
 ## Code changes
@@ -136,7 +136,7 @@ var running_on_apple_tv = Platform.isTVOS;
 - _TV remote/keyboard input_: A new native class, `RCTTVRemoteHandler`, sets up gesture recognizers for TV remote events. When TV remote events occur, this class fires notifications that are picked up by `RCTTVNavigationEventEmitter` (a subclass of `RCTEventEmitter`), that fires a JS event. This event will be picked up by instances of the `TVEventHandler` JavaScript object. Application code that needs to implement custom handling of TV remote events can create an instance of `TVEventHandler` and listen for these events, as in the following code:
 
 ```tsx
-var TVEventHandler = require('TVEventHandler');
+const TVEventHandler = require('TVEventHandler');
 
 class Game2048 extends React.Component {
   _tvEventHandler: any;

docs/clipboard.md

@@ -79,7 +79,7 @@ Get content of string type, this method returns a `Promise`, so you can use foll
 
 ```jsx
 async _getContent() {
-  var content = await Clipboard.getString();
+  const content = await Clipboard.getString();
 }
 ```
 

docs/images.md

@@ -51,13 +51,13 @@ In order for this to work, the image name in `require` has to be known staticall
 <Image source={require('./my-icon.png')} />;
 
 // BAD
-var icon = this.props.active
+const icon = this.props.active
   ? 'my-icon-active'
   : 'my-icon-inactive';
 <Image source={require('./' + icon + '.png')} />;
 
 // GOOD
-var icon = this.props.active
+const icon = this.props.active
   ? require('./my-icon-active.png')
   : require('./my-icon-inactive.png');
 <Image source={icon} />;

docs/interactionmanager.md

@@ -26,7 +26,7 @@ The touch handling system considers one or more active touches to be an 'interac
 InteractionManager also allows applications to register animations by creating an interaction 'handle' on animation start, and clearing it upon completion:
 
 ```tsx
-var handle = InteractionManager.createInteractionHandle();
+const handle = InteractionManager.createInteractionHandle();
 // run animation... (`runAfterInteractions` tasks are queued)
 // later, on animation completion:
 InteractionManager.clearInteractionHandle(handle);

docs/native-components-ios.md

@@ -125,7 +125,7 @@ MapView.propTypes = {
   zoomEnabled: PropTypes.bool,
 };
 
-var RNTMap = requireNativeComponent('RNTMap');
+const RNTMap = requireNativeComponent('RNTMap');
 
 module.exports = MapView;
 ```
@@ -221,7 +221,7 @@ MapView.propTypes = {
 
 ```tsx title="MyApp.tsx"
 render() {
-  var region = {
+  const region = {
     latitude: 37.48,
     longitude: -122.16,
     latitudeDelta: 0.1,
@@ -354,7 +354,7 @@ class MyApp extends React.Component {
   }
 
   render() {
-    var region = {
+    const region = {
       latitude: 37.48,
       longitude: -122.16,
       latitudeDelta: 0.1,
@@ -450,7 +450,7 @@ Since all our native react views are subclasses of `UIView`, most style attribut
 
 ```tsx title="DatePickerIOS.ios.tsx"
 import {UIManager} from 'react-native';
-var RCTDatePickerIOSConsts = UIManager.RCTDatePicker.Constants;
+const RCTDatePickerIOSConsts = UIManager.RCTDatePicker.Constants;
 ...
   render: function() {
     return (
@@ -465,7 +465,7 @@ var RCTDatePickerIOSConsts = UIManager.RCTDatePicker.Constants;
   }
 });
 
-var styles = StyleSheet.create({
+const styles = StyleSheet.create({
   rkDatePickerIOS: {
     height: RCTDatePickerIOSConsts.ComponentHeight,
     width: RCTDatePickerIOSConsts.ComponentWidth,

docs/network.md

@@ -190,7 +190,7 @@ export default App;
 The [XMLHttpRequest API](https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest) is built into React Native. This means that you can use third party libraries such as [frisbee](https://github.com/niftylettuce/frisbee) or [axios](https://github.com/axios/axios) that depend on it, or you can use the XMLHttpRequest API directly if you prefer.
 
 ```tsx
-var request = new XMLHttpRequest();
+const request = new XMLHttpRequest();
 request.onreadystatechange = e => {
   if (request.readyState !== 4) {
     return;
@@ -214,7 +214,7 @@ request.send();
 React Native also supports [WebSockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket), a protocol which provides full-duplex communication channels over a single TCP connection.
 
 ```tsx
-var ws = new WebSocket('ws://host.com/path');
+const ws = new WebSocket('ws://host.com/path');
 
 ws.onopen = () => {
   // connection opened

website/blog/2016-03-24-introducing-hot-reloading.md

@@ -85,10 +85,10 @@ This invocation wraps each module's code into an anonymous function which we gen
 
 So say you start your app and require `log`. At this point, neither `log` nor `time`'s factory functions have been executed so no exports have been cached. Then, the user modifies `time` to return the date in `MM/DD`:
 
-```
+```js
 // time.js
 function bar() {
-  var date = new Date();
+  const date = new Date();
   return `${date.getMonth() + 1}/${date.getDate()}`;
 }