CODE EXAMPLE FOR JAVASCRIPT

react native communicate with webview

<WebView
    source={{uri: "myweb.com/webview.php"}}
    injectedJavaScript={injectedJs}
    startInLoadingState
    javaScriptEnabledAndroid={true}
    javaScriptEnabled={true}
    onMessage={event => {
      alert('MESSAGE >>>>' + event.nativeEvent.data);
    }}
/>