--- id: props title: Props layout: docs category: The Basics permalink: docs/props.html next: state previous: tutorial --- Most components can be customized when they are created, with different parameters. These creation parameters are called `props`. For example, one basic React Native component is the `Image`. When you create an image, you can use a prop named `source` to control what image it shows. ```ReactNativeWebPlayer import React, { Component } from 'react'; import { AppRegistry, Image } from 'react-native'; class Bananas extends Component { render() { let pic = { uri: 'https://upload.wikimedia.org/wikipedia/commons/d/de/Bananavarieties.jpg' }; return ( ); } } AppRegistry.registerComponent('Bananas', () => Bananas); ``` Notice that `{pic}` is surrounded by braces, to embed the variable `pic` into JSX. You can put any JavaScript expression inside braces in JSX. Your own components can also use `props`. This lets you make a single component that is used in many different places in your app, with slightly different properties in each place. Just refer to `this.props` in your `render` function. Here's an example: ```ReactNativeWebPlayer import React, { Component } from 'react'; import { AppRegistry, Text, View } from 'react-native'; class Greeting extends Component { render() { return ( Hello {this.props.name}! ); } } class LotsOfGreetings extends Component { render() { return ( ); } } AppRegistry.registerComponent('LotsOfGreetings', () => LotsOfGreetings); ``` Using `name` as a prop lets us customize the `Greeting` component, so we can reuse that component for each of our greetings. This example also uses the `Greeting` component in JSX, just like the built-in components. The power to do this is what makes React so cool - if you find yourself wishing that you had a different set of UI primitives to work with, you just invent new ones. The other new thing going on here is the [`View`](/react-native/docs/view.html) component. A [`View`](/react-native/docs/view.html) is useful as a container for other components, to help control style and layout. With `props` and the basic [`Text`](/react-native/docs/text.html), [`Image`](/react-native/docs/image.html), and [`View`](/react-native/docs/view.html) components, you can build a wide variety of static screens. To learn how to make your app change over time, you need to [learn about State](/react-native/docs/state.html).