React Native Alert – How to Show Alert in React Native

React Native Alert

In this post, we will see How to Show Alert in React Native. React Native Alert is a component to show Alert.

Following are the different type of Alerts in React Native:

• Simple Alert.
• Two Option Alert.
• Three Option.

For IOS You can add more option but for Android, it only supports three options max after that you have to make your own custom alert.

To Import Alert in Code

import { Alert} from 'react-native'

Render Using

Alert.alert(
  'Heading',
  'Body',
  [{
    text: 'option1',
    onPress: () => handler
  },..]
)

To Make a React Native App

Getting started with React Native will help you to know more about the way you can make a React Native project. We are going to use react native command line interface to make our React Native App.

If you have previously installed a global react-native-cli package, please remove it as it may cause unexpected issues:

npm uninstall -g react-native-cli @react-native-community/cli

Run the following commands to create a new React Native project

npx react-native init ProjectName

If you want to start a new project with a specific React Native version, you can use the --version argument:

npx react-native init ProjectName --version X.XX.X

Note If the above command is failing, you may have old version of react-native or react-native-cli installed globally on your pc. Try uninstalling the cli and run the cli using npx.

This will make a project structure with an index file named App.js in your project directory.

Code

Open App.js in any code editor and replace the code with the following code

App.js

//React Native Alert
//https://aboutreact.com/react-native-alert/

//import React in our code
import React from 'react';

//import all the components we are going to use
import {
  Alert,
  Button,
  View,
  SafeAreaView,
  StyleSheet
} from 'react-native';

const App = () => {
  const simpleAlertHandler = () => {
    //function to make simple alert
    alert('Hello I am Simple Alert');
  };

  const twoOptionAlertHandler = () => {
    //function to make two option alert
    Alert.alert(
      //title
      'Hello',
      //body
      'I am two option alert. Do you want to cancel me ?',
      [
        {
          text: 'Yes',
          onPress: () => console.log('Yes Pressed')
        },
        {
          text: 'No',
          onPress: () => console.log('No Pressed'), style: 'cancel'
        },
      ],
      {cancelable: false},
      //clicking out side of alert will not cancel
    );
  };

  const threeOptionAlertHandler = () => {
    //function to make three option alert
    Alert.alert(
      //title
      'Hello',
      //body
      'I am three option alert. Do you want to cancel me ?',
      [
        {
          text: 'May be',
          onPress: () => console.log('May be Pressed')
        },
        {
          text: 'Yes', onPress: () => console.log('Yes Pressed')
        },
        {
          text: 'OK', onPress: () => console.log('OK Pressed')
        },
      ],
      {cancelable: true},
    );
  };

  return (
    <SafeAreaView style={{flex: 1}}>
      <View style={styles.container}>
        {/*To generate simple alert*/}
        <Button
          title="Simple Alert"
          onPress={simpleAlertHandler} />
        {/*To generate two option alert*/}
        <Button
          title="Alert with Two Options"
          onPress={twoOptionAlertHandler}
        />
        {/*To generate three option alert*/}
        <Button
          title="Alert with Three Options"
          onPress={threeOptionAlertHandler}
        />
      </View>
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    backgroundColor: '#ecf0f1',
  },
});

export default App;

To Run the React Native App

Open the terminal again and jump into your project using.

cd ProjectName

1. Start Metro Bundler

First, you will need to start Metro, the JavaScript bundler that ships with React Native. To start Metro bundler run following command:

npx react-native start

Once you start Metro Bundler it will run forever on your terminal until you close it. Let Metro Bundler run in its own terminal. Open a new terminal and run the application.

2. Start React Native Application

To run the project on an Android Virtual Device or on real debugging device:

npx react-native run-android

or on the iOS Simulator by running (macOS only)

npx react-native run-ios

Output Screenshot

IOS

Android

Output in Online Emulator

That was the React Native Alert. If you have any doubt or you want to share something about the topic you can comment below or contact us here. The remaining components will be covered in the next article. Stay tuned!

Hope you liked it. 🙂