Unable to run sample app second time on React Js [closed]

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Looks like a version issue with some lib in your node_modules.,Try Deleting the node_modules folder.,Remove ^ symbol against all the version numbers in your package.json, Calculating the sum of means of lists as `n` approaches infinity

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However, having import/export in your React bundled app does not mean that you can just use them anywhere you want! For example, if you’re also doing server-side rendering through the latest Node, things will not work for you. You will most likely get an "unexpected token" error.,When importing from react and react-dom, make sure that you’re importing the correct names and what you’re using is exactly the same as what you’re importing. ESLint can help you point out what is not being used.,To identify the process that’s using a certain port, you can either use a command like ps (and grep for something about your app) or if you know the port number you can use the lsof command:,The popular configuration of a React project uses Webpack and Babel. Both allow the use of this feature and compile it down to something all browsers can understand. You can only use import/export if you have something like Webpack or Babel in your flow.

class greeting extends React.Component {
   // ...
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The Metro bundler runs on port 8081. If another process is already using that port, you can either terminate that process, or change the port that the bundler uses.,You can configure the bundler to use a port other than 8081 by using the port parameter:,Then run the following to terminate the process:,On Windows you can find the process using port 8081 using Resource Monitor and stop it using Task Manager.

sudo lsof - i: 8081
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We’ve prepared an example repository demonstrating how to lazy-load an older version of React if necessary. This demo uses Create React App, but it should be possible to follow a similar approach with any other tool. We welcome demos using other tooling as pull requests.,Technically, it has always been possible to nest apps developed with different versions of React. However, it was rather fragile because of how the React event system worked.,In React components, you usually write event handlers inline:,Disable console in the second render pass of DEV mode double render. (@sebmarkbage in #18547)

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npm eject: to eject from create-react-app,An introduction to ReactHow to use create-react-app,When you build a React application using create-react-app, you have many options at your disposal when it comes to styling.,If you don’t use create-react-app you need to setup Babel yourself.

In this case, you add 2 script tags to the end of the body tag:


   <script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.3/umd/react.development.js" crossorigin></script>
   <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.3/umd/react-dom.production.min.js" crossorigin></script>

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Running the example app,React Native date & time picker component for iOS, Android and Windows.,react-native-component,npm i @react-native-community/datetimepicker

npm install @react - native - community / datetimepicker--save
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Before adding the tests, we need to find out what the app does. The best way to do this is to clone the app and run it locally. To clone the application and install its dependencies run:,In the run step, we use npm ci to install our project dependencies.,Presentational and container components,The second call happens inside handleRefreshClick

Before adding the tests, we need to find out what the app does. The best way to do this is to clone the app and run it locally. To clone the application and install its dependencies run:

git clone https: //github.com/reactjs/redux.git
   cd redux / examples / async
git checkout db5f8d1
npm install
npm start
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