React 导航示例 JS 语法

React navigation example JS grammar

我不明白 navigation 来自哪里(第 46-48 行):

https://github.com/react-community/react-navigation/blob/master/examples/NavigationPlayground/js/StacksOverTabs.js

const MyHomeScreen = ({ navigation }) => ( <MyNavScreen banner="Home Screen" navigation={navigation} /> );

等于

class MyHomeScreen extends React.Component{

constructor(props){
    super(props);
}

render(){

    const {navigation} = this.props;

    return <MyNavScreen banner="Home Screen" navigation={navigation} />
}}