how to use platform.select

                                     import {Platform} from 'react-native';
    st styles = StyleSheet.create({
      container: {
        flex: 1,
        ...Platform.select({
          ios: {
            backgroundColor: 'red',
          },
          android: {
            backgroundColor: 'blue',
          },
        }),
      },
    });

                                      const design = Platform.select({
    android: {
      header: true
    },
    ios: {
	  header: false
    },
  });