React Native Switch

React Native Switch

This post will give you a basic Understanding of React Native switch. React Native Switch is a component for getting/showing the boolean value or to select from one out of two.

A Switch is a controlled component that requires a callback onValueChange that updates the value prop in order for the component to reflect user actions. If the value prop is not updated, the component will continue to render the supplied value prop instead of the expected result of any user actions.

To Import Switch in Code

import { Switch} from 'react-native'

Render Using

<Switch
  onValueChange = {handlerHere}
  value = {Pre decided value if any}
/>

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 Switch
//https://aboutreact.com/react-native-switch/

//import React in our code
import React, {useState} from 'react';

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

const App = () => {
  const [switchValue, setSwitchValue] = useState(false);

  const toggleSwitch = (value) => {
    //To handle switch toggle
    setSwitchValue(value);
    //State changes according to switch
  };

  return (
    <SafeAreaView style={{flex: 1}}>
      <View style={styles.container}>
        {/*To show Switch state*/}
        <Text>
          {switchValue ? 'Switch is ON' : 'Switch is OFF'}
        </Text>
        {/*Setting the default value of state*/}
        {/*On change of switch onValueChange will be triggered*/}
        <Switch
          style={{marginTop: 30}}
          onValueChange={toggleSwitch}
          value={switchValue}
        />
      </View>
    </SafeAreaView>
  );
};

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

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

Output in Online Emulator

That was the React Native Switch. If you have any doubts 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. 🙂