React Native Props

The properties of React Native components are simply pronounced as props. In React Native, most of the components can be customised at the time of their creation with different parameters. These parameters are known as props. They are immutable, and they cannot be changed.

One of the examples of props is a source property if Image component which controls the image is displayed over the device screen.

React Native Default custom Props

1.  import React, { Component } from 'react';  
2. import {  
3.   Platform,  
4.   StyleSheet,  
5.   Image,  
6.   Text,  
7.   View  
8. } from 'react-native';  
9.   
10.   
11. export default class App extends Component<{}> {  
12.   render() {  
13.     let imagePath = { uri: 'https://facebook.github.io/react-native/img/header_logo.png'};  
14.     return (  
15.         <View style={styles.container}>  
16.           <Text style={styles.welcome}>Welcome to React Native!</Text>  
17.           <Image source={imagePath} style={{width: 250, height: 250}} />  
18.         </View>  
19.     );  
20.   }  
21. }  
22.   
23. const styles = StyleSheet.create({  
24.   container: {  
25.     flex: 1,  
26.     justifyContent: 'center',  
27.     alignItems: 'center',  
28.     backgroundColor: '#a7a6a9',  
29.   },  
30.   welcome: {  
31.     fontSize: 30,  
32.     textAlign: 'center',  
33.     margin: 20,  
34.   }  
35. });  

Output:

Using props in our own Component

We can also use props in our components. A single component can be used in many different places in the app by making slightly different properties in each place. To implement the props in our component, this.props is applied followed by the property.

For example, one of the basic React Native components is Text. When we create a Text component, we can use a prop "name" as props to control its appearance. We also apply the StyleSheet to the component which is used as our component.

App.js

1.  import React, { Component } from 'react';  
2. import { StyleSheet, Text, View } from 'react-native';  
3.   
4. class ChildClass extends Component {  
5.   render() {  
6.     return (  
7.         <View style={{alignItems: 'center'}}>  
8.           <Text style={styles.welcome}>Hello {this.props.name}!</Text>  
9.         </View>  
10.     );  
11.   }  
12. }  
13.   
14. export default class ParentsClass extends Component {  
15.   render() {  
16.     return (  
17.         <View style={{alignItems: 'center'}}>  
18.           <ChildClass name='Ashu' />  
19.           <ChildClass name='Aman' />  
20.           <ChildClass name='Max' />  
21.         </View>  
22.     );  
23.   }  
24. }  
25. const styles = StyleSheet.create({  
26.    welcome: {  
27.     fontSize: 30,  
28.   }  
29. });  
30.   
31. // skip this line if using Create React Native App  
32. //AppRegistry.registerComponent('MyReactNativeApp', () => ParentsClass);  

Output: